CHoPP Computer Corporation (CHoPP) appeals from the district court’s summary judgment in favor of the United States and PaineWebber Incorporated (PaineWebber), in CHoPP’s action for damages arising from an alleged wrongful levy of funds contained in a PaineWebber account. We have jurisdiction under 28 U.S.C. § 1291 , and we affirm.

I

Alex Laurins, a former investment promoter, controlled the PaineWebber. account. The competing claims to that account arose from separate actions that CHoPP and the United States had pursued against Laurins.

CHoPP sued Laurins and others in 1986, contending that they had engaged in a scheme to disparage CHoPP and thereby drive down the price of CHoPP’s stock, so that Laurins and others could profit from short sales of that stock. CHoPP sought to recover profits from the short sale of its stock, wherever found, that resulted from the tortious disparagement. CHoPP obtained a preliminary injunction from the Superior Court for the City and County of San Francisco. That injunction provided, in relevant part:

CHoPP Computer Corp. v. Laurins, No. 862163, slip. op. at 2 (Cal.Sup.Ct. Aug. 25, 1986) (preliminary injunction). Neither the United States nor PaineWebber was a party to CHoPP’s state court action.

Meanwhile, as CHoPP’s suit against Lau-rins was pending, the United States had launched a .tax investigation against one of *1346 Laurins’ alter ego companies. 1 Laurins’ continuing failure to comply with a discovery order of the federal court resulted in a penalty of $444,000, which the United States reduced to judgment. Subsequently, Laurins was convicted in federal court of obstruction of justice and criminal contempt, and was fined $250,000 (and sentenced to a prison term). 2

The United States then obtained two writs of execution to collect the judgment and fine, which together totalled $694,000. The Government learned of the PaineWebber account that Laurins controlled, and it served the broker with the writs. On February 17, 1990, CHoPP notified the United States of the state court injunction freezing Laurins’ short-sale proceeds. The PaineWebber account contained short-sale positions. Paine-Webber notified the United States that it would not cooperate in the levy unless the United States obtained a court order requiring PaineWebber to disburse the money. The Government obtained the order from the federal district court (without informing that court of the existence of the injunction), and PaineWebber delivered $694,000 from the account to the government.

In March 1990, CHoPP submitted an administrative claim for $694,000 under the Federal Tort Claims Act (FTCA), 28 U.S.C. § 1346 (b) (1988). The Attorney General denied CHoPP’s claim in August of that year.

Then, in October 1990, after a jury trial, CHoPP and a coplaintiff obtained a judgment in excess of $29 million against the defendants in the state court action. See CHoPP Computer Corp. v. Laurins, No. 862163, slip, op. at 2 (Cal.Sup.Ct. Oct. 25, 1990) (final judgment). 3 The superior court judgment provided:

Id., slip. op. at 2-3. Pursuant to this judgment, PaineWebber delivered to CHoPP approximately $263,000 that remained in the account.

CHoPP then brought this action against the Government and PaineWebber in the United States District Court for the Northern District of California. CHoPP averred that it had a prior claim to the PaineWebber account. It alleged that the Government’s levy and retention of the funds were conversions under California law and the FTCA. It further alleged that PaineWebber’s acquiescence in the levy was a conversion. CHoPP also claimed that each defendant had violated the preliminary injunction. The district court granted the defendants’ motions for summary judgment and denied CHoPP’s cross-motion for summary judgment.

We review summary judgments de novo. Jones v. Union Pac. R.R., 968 F.2d 937, 940 (9th Cir.1992). In this case there are no disputed material facts. The United States and PaineWebber each knew of the preliminary injunction at the time of the levy. The United States concedes that it refused to return the levied funds to CHoPP after the state court’s final judgment had been entered. We therefore ask only whether the district court correctly applied the relevant substantive law. See Federal Deposit Ins. Corp. v. O’Melveny & Meyers, 969 F.2d 744, 747 (9th Cir.1992).

*1347 II

California provides the relevant substantive law in this case. That state permits recovery on a conversion theory either for the wrongful taking or for the wrongful retention of property. See Edwards v. Jenkins, 214 Cal. 713 , 7 P.2d 702, 705 (1932). In order to maintain an action for conversion, CHoPP must show that it had title to or a right to possess the funds in the Paine-Webber account. Moore v. Regents of the Univ. of Cal., 51 Cal.3d 120 , 271 Cal.Rptr. 146, 155 , 793 P.2d 479, 488 (1990), cert. denied, 499 U.S. 936 , 111 S.Ct. 1388 , 113 L.Ed.2d 444 (1991); Baldwin v. Marina City Properties, Inc., 79 Cal.App.3d 393 , 145 Cal.Rptr. 406, 416 (1978). CHoPP’s interest must have existed, if at all, at the time of the levy or at the time that CHoPP demanded return of the funds after entry of the final judgment in state court.

A

We pause to consider whether Congress has waived the sovereign immunity of the United States for a conversion, as California law defines that tort. The FTCA subjects the United States to monetary liability for

28 U.S.C. § 1346 (b) (1988). The United States contends here that because California views a conversion as a strict liability tort, e.g., Moore, 271 Cal.Rptr. at 161 , 793 P.2d at 494 & n. 38, CHoPP’s conversion claim is beyond the scope of the FTCA. We disagree.

This Circuit has declined previously to address the Government’s strict liability argument. Gardiner Mfg. Co. v. United States, 479 F.2d 39 , 41 n. 2 (9th Cir.1973). 4 A recent district court opinion, however, squarely rejects the Government’s position. Nottingham, Ltd. v. United States, 741 F.Supp. 1447, 1448-49 (C.D.Cal.1991). Nottingham analogizes a conversion to a trespass, which the Supreme Court has determined gives rise to FTCA liability, notwithstanding that wrongful intent is not an element of trespass. Id. (citing Hatahley v. United States, 351 U.S. 173, 181 , 76 S.Ct. 745, 751 , 100 L.Ed. 1065 (1956)). Nottingham further distinguishes a conversion from the class of torts involving ultrahazardous activities, which indisputably are beyond the scope of the FTCA. Id. at 1448 (distinguishing Dalehite v. United States, 346 U.S. 15, 44-45 , 73 S.Ct. 956, 972-973 , 97 L.Ed. 1427 (1953)). We adopt the well-reasoned analysis and conclusion of Judge Tashima’s Nottingham opinion, and hold that CHoPP’s conversion claim can be brought under the FTCA.

B

CHoPP offers two theories to support its claim that it owned or had a right to possess the PaineWebber account at the time of the government’s levy. First, CHoPP argues that the state court’s final judgment collaterally estops the United States from denying CHoPP’s ownership. We see no reason why that should be so. The United States was neither a party nor a privy of any party in the state court action. See Dillard v. McKnight, 34 Cal.2d 209 , 209 P.2d 387, 391 (1949). The government sought nothing, nor was anything sought from it, in the state court action, directly or indirectly. The government levied on the PaineWebber funds independently of the state court action and prior to entry of the state judgment; the United States accordingly does not acquire the status of privy by becoming “ ‘one who, after rendition of the judgment, has acquired an interest in the subject matter affected by the judgment through or under one of the *1348 parties.’ ” Boulter v. Commercial Standard Ins. Co., 175 F.2d 763, 768 (9th Cir.1949) (quoting Bernhard v. Bank of America, 19 Cal.2d 807 , 122 P.2d 892, 894 (1942) (emphasis added by Boulter)); cf. In re Mellor, 734 F.2d 1396 , 1401 n. 4 (9th Cir.1984) (judgment lienholder “subject to all prior interests in the property”) (emphasis added). The United States is not estopped by the state court judgment from denying CHoPP’s title to the funds.

CHoPP’s next argument is that it had an ownership interest in the PaineWebber account at the time of the levy by reason of the constructive trust. There is California authority that suggests that a constructive trust springs into existence at the moment a wrongful taking occurs. See, e.g., Broder v. Conklin, 121 Cal. 282 , 53 P. 699, 702 (1898) (holding that the statute of limitation begins to run when harm arises); Majewsky v. Empire Construction Co., 2 Cal.3d 478 , 85 Cal.Rptr. 819 , 828 n. 4, 467 P.2d 547 , 556 n. 4 (1970) (Tobriner, J., dissenting) (“the imposition of a constructive trust restores title to plaintiff ab initio”). We do not agree, however, that cases dealing with limitations or other rights between the “trustor” and “trustee” of a constructive trust establish that the imposition of a constructive trust may, under California law, interfere with a third party’s prior claim that has been reduced to judgment and levied upon.

The retroactive creation of a constructive trust is not necessarily a self-executing award of equitable title. See George G. Bogert and George T. Bogert, The Law of Trusts and Trustees Section 472 (Rev.2d ed. 1978); cf. United States v. 92 Buena Vista Ave., — U.S. —,—, 113 S.Ct. 1126, 1135-36 , 122 L.Ed.2d 469 (1993) (plurality op.) (involving the common-law relation back doctrine). There is no California law that suggests that CHoPP .may rely upon a 1990 judgment to impede satisfaction in 1988 of a competing judgment that was already final. Nor did the preliminary injunction give CHoPP a prior claim. The preliminary injunction was not final, was not addressed to others than the parties, and did not purport to impose a trust on the res of the Paine-Webber account. Only the final state court judgment recognized the existence of a constructive trust, and it came too late for the purpose of defeating the earlier levy of the United States.

CHoPP’s view to the contrary, if adopted, would cause disruption that we conclude would not be countenanced by California law. If a retroactive creation of a constructive trust may defeat a prior and otherwise legal levy, one creditor may deter competitors from satisfying their judgments against a common debtor merely by initiating an action that seeks recognition of a constructive trust over the debtor’s assets. A third party who proceeded with a levy under those circumstances could be held liable for a conversion.

California experienced a similar problem with its lis pendens procedure. In one case the state court of appeal allowed the filing of a lis pendens on a defendant’s home in connection with a fraud suit seeking to impose a constructive trust on the home. Coppinger v. Superior Court, 134 Cal.App.3d 883 , 185 Cal.Rptr. 24, 29-30 (1982). Coppinger has since been sharply criticized, perhaps most aptly in Urez Corp. v. Superior Court, 190 Cal.App.3d 1141 , 235 Cal.Rtpr. 837, 842-43 (1987):

Even allowing for the special context of lis pendens, we view Urez as a clear indication that California discourages the use of equitable remedies to ward off competing prior lienholders. “Where, as here, the purpose of the constructive trust is only to secure payment of a debt, the plaintiff, like other creditors must rely upon prejudgment attachment procedures.” La Paglia v. Superior Court, 215 Cal.App.3d 1322 , 264 Cal.Rptr. 63, 68 (1989); cf. Doyka v. Superior Court, 233 Cal.App.3d 1134 , 285 Cal.Rptr. 14, 16 (1991) (general injunction freezing defendant’s assets pending litigation invalid as amounting to a prejudgment attachment without meeting requirements for attachment).

Our view intimates no characterization of the United States as an innocent transferee. As a judgment lienholder, the Government was ineligible for that status. In re Mellor, 734 F.2d 1396 , 1401 n. 4 (9th Cir.1984). Moreover, the Government’s motive is irrelevant to the success or failure of the conversion claim. See Poggi v. Scott, 167 Cal. 372 , 139 P. 815, 816 (1914); 5 B.E. Witkin, Summary of California Law § 624 (9th ed. 1988) [hereafter Witkin, Summary ]. Rather, our view is founded in California’s preference, expressed in Urez, 235 Cal.Rptr. at 843 , that all creditors adhere to even-handed collection rules. We determine, therefore, that the imposition of a constructive trust did not give CHoPP title to the PaineWebber account at the time of the Government’s levy. It follows that the United States did not commit a conversion when it levied, and PaineWebber did not commit conversion when it surrendered the funds.

C

CHoPP crafts two theories which it argues relieves it of the burden of showing contemporaneous ownership of the account. First, CHoPP contends that the government’s levy was ineffective under California Code of Civil Procedure section 700.180(b), which reaches any “levy upon property that is the subject of-an action ... pending at the time of the levy.” 5 Although there is no California authority interpreting section 700.-180(b), we conclude that CHoPP’s state court action lies beyond the plain language of that provision. We read the phrase “property that is the subject of an action” in its commonly understood meaning: property that is the subject of an action brought to determine who has interests in it. See, e.g., Evarts v. Jones, 127 Cal.App.2d 623 , 274 P.2d 185, 187 (1954) (“a grantee who acquires title with constructive notice of the pendency of an action to quiet title against his grantor is concluded by a judgment against-the latter”). CHoPP’s state court action was not one to determine ownership of the PaineWebber account, but rather one to establish Laurins’ civil liability to CHoPP.

The constructive trust is only a remedy. Stansfield v. Starkey, 220 Cal.App.3d 59 , 269 Cal.Rptr. 337, 347 (1990). While such a trust may arise in a case where the trust res is the subject of the action, as in a suit for specific performance of a real estate contract, that is not the case here. The state court imposed the trust as a means to assist CHoPP in recovering the damages which the jury had awarded for the tort of fraudulent disparagement. That tangential employment of the remedy did not render the PaineWebber account the “subject of an action ... pending at the time of the levy....” Cal.Civ.Proc. § 700.180(b) (1987).

The analogy to the lis pendens procedure again offers guidance. In that context, the California Court of Appeal has specified that the assertion of a constructive trust is insufficient to prevent the transfer of property that could serve as the res of the trust:

Urez, 235 Cal.Rptr at 842. We find the analogy apt in this ease; the subject of CHoPP’s action was not the PaineWebber account.

CHoPP next attempts to rely on California case law that permits a plaintiff with title to property, but lacking a right to immediate possession, to maintain a conversion action. CHoPP relies on Taylor v. S & M Lamp Co., 190 Cal.App.2d 700 , 12 Cal.Rptr. 323 (1961), and Reynolds v. Lerman, 138 Cal.App.2d 586 , 292 P.2d 559 (1956), both of which ruled that a plaintiff with title need not have a right to possession to bring a conversion claim. These cases are not of aid to CHoPP, however, because CHoPP has shown neither title nor a right to possession. As we have held above, CHoPP did not hold equitable title to the PaineWebber account at the time of the levy. 6

D

CHoPP responds that, even if the United’ States did not commit conversion when it levied upon the PaineWebber account, it did so later when it refused to yield the proceeds up to CHoPP after the state court entered its final judgment. CHoPP failed to raise this wrongful retention claim in its original pleadings. In conjunction with a motion to reconsider, CHoPP requested leave to amend to assert that claim. The district court denied the motion to reconsider, and entered summary judgment in favor of the United States, without giving explicit consideration to CHoPP’s request. We interpret the district court’s action as an implicit denial of the request for leave to amend. We review that denial for an abuse of discretion, but are mindful of the'-strong policy in favor of permitting amendment. Texaco, Inc. v. Ponsoldt, 939 F.2d 794, 798 (9th Cir.1991).

What we have said already makes it clear that the district court did not abuse its discretion in denying leave to amend, for the amendment to state a wrongful retention claim would have been futile. We have rejected CHoPP’s contention that the constructive trust vested title retroactively, at least in a manner that would render tortious prior levies by judgment creditors. CHoPP is simply not in the position of a plaintiff who seeks return of an identifiable res wrongfully taken or wrongfully retained. See, e.g., People v. One 1960 Ford, 228 Cal.App.2d 571 , 39 Cal.Rptr. 636, 638 (1964) (a true owner of misappropriated property stands above a mere creditor). CHoPP sought damages for fraud, and intended to pursue, with the state court’s help, the PaineWebber funds as a means of satisfying its judgment. The United States, armed with its own prior, valid judgments, pursued the same funds and got there first. There was no flaw in the United States’ title when it acquired the funds, and none appears now.

CHoPP bears the'burden of persuading us that it may bring this action. In a conversion case a “plaintiff must recover, if at all, upon the strength of his own title and not upon the weakness of his adversary....” Lee On v. Long, 37 Cal.2d 499 , 234 P.2d 9, 12 (1951) (citation omitted), cert. denied, 342 U.S. 947 , 72 S.Ct. 553 , 96 L.Ed. 704 (1952). The constructive trust, once imposed, undoubtedly gave CHoPP “some kind of an equitable interest” in the account, Restatement of Restitution, § 160 cmt. a (1937), but that interest was recognized after the government had made a perfectly lawful levy on the PaineWebber account. CHoPP’s late-perfected interest is too weak to overcome the present ownership and possessory interest of the United States, lawfully acquired. To hold otherwise would permit CHoPP to gain priority over a preexisting judgment creditor that had satisfied its debt by levy of execution. We are unpersuaded that California courts would sanction that result. We therefore find no abuse of discretion in the *1351 district court’s failure to permit amendment of the complaint.

Ill

CHoPP also seeks damages from the United States and PaineWebber on the ground that each violated the state court preliminary injunction. That injunction barred the transfer of funds from the PaineWebber account. The defendants maintain that they were not subject to the injunction.

We consider the threshold question whether civil damages are available under California law for the disobedience of a preliminary injunction. A civil contempt proceeding is the usual method of enforcement, 6 B.E. Witkin, California Procedure § 321 (3d ed. 1985), but we conclude that damages also may be awarded. One California court has observed:

Kirby v. San Francisco Savings & Loan Soc’y, 95 Cal.App. 757 , 273 P. 609, 609-10 (1928); see also Heinz v. Superior Court, 42 Cal.2d 164 , 266 P.2d 5, 12 (1954) (civil damages may be collected for an act otherwise in contempt).

A

CHoPP concedes that the United States was neither a party, nor a privy to a party, named in the injunction. CHoPP argues that the government is bound as a successor in interest to Laurins. We disagree. Although California recognizes the concept of corporate succession, see 6 Witkin, Summary § 320, CHoPP cites no authority which supports the idea that the act of execution renders a judgment creditor subject to an injunction that bound the judgment debt- or.

B

CHoPP concedes that PaineWebber, also, was not a party to the injunction. Paine-Webber was bound, argues CHoPP, because it was Laurins’ agent. An injunction binds the agent of a party named in the injunction, Ross v. Superior Court, 19 Cal.3d 899 , 141 Cal.Rptr. 133, 138 , 569 P.2d 727, 731 (1977), and a broker is ordinarily its client’s agent. See, e.g., Black v. Shearson, Hammill & Co., 266 Cal.App.2d 362 , 72 Cal.Rptr. 157, 160 (1968) (affirming judgment against brokers who defrauded clients).

We conclude, however, that PaineWebber acted on its own authority, and not as Lau-rins’ agent, when it released funds from Lau-rins’ account to the United States. The broker presumably acted against its client’s wishes, but its action complied with a valid levy backed up by a court order. This ease therefore differs markedly from Kirby , the primary case in support of CHoPP’s position. There, a bank released funds to a defendant named in the injunction. Kirby, 273 P. at 609 . 7 Because PaineWebber was not bound as an agent by the injunction against Lau-rins, it incurred no liability for complying with the levy. 8

IV

The United States and PaineWebber were entitled to summary judgment. CHoPP has no viable claim against either defendant for conversion of funds or for violation of an *1352 injunction. The judgment of the district court is

AFFIRMED.

. The alter ego company was Gold Depository & Trust Company.

. We affirmed his convictions. See United States v. Laurins, 857 F.2d 529 (9th Cir.1988), cert. denied, 492 U.S. 906 , 109 S.Ct. 3215 , 106 L.Ed.2d 565 (1989).

.Laurins was in bankruptcy at this time, and the Superior Court had severed CHoPP’s claims against him from the rest of the case. However, the nominal owner of the PaineWebber account, Laurins’ Co-Op International Trust, remained subject to the final judgment.

. We have recognized a conversion claim under the FTCA on an unrelated basis. See Love v. United States, 915 F.2d 1242, 1245-47 (9th Cir.1989) (holding that federal loan recipients may bring a state law conversion claim to undo a foreclosure, notwithstanding their entitlement to seek recovery for breach of contract under the Tucker Act, 28 U.S.C. §§ 1346 (a)(2), 1491 (1988)).

. Section 700.180(a) sets out certain categories of property, none of which are involved here, that "may be levied upon pursuant to this article notwithstanding that the property levied upon is the subject of a pending action or special proceeding.”

Section 700.180(b) then provides:

. CHoPP’s reliance on these cases is also defeated by our finding that neither the United States nor PaineWebber was subject to, or in violation of, the preliminary injunctions. See infra section III.

. Kirby specifically addressed whether the bank could be held liable for violating an injunction on an aiding and abetting theory. See id. See id. 273 P. at 610 ("it is not claimed that the defendant acted as the agent or servant of Kirby”).

. Because we determine that PaineWebber was not subject to the injunction, we do not address what effect the court order enforcing the levy could be given if it conflicted with the injunction.