Hillis

We must decide whether a defendant who files a counterclaim or a third-party complaint waives the asserted defense of improper venue under Federal Rule of Civil Procedure 12(b)(3). We hold that filing a counterclaim or a third-party complaint does not waive the defense of improper venue.

I

In 2006, Steve and Diane Hillis were solicited by John Fox, who had been retained by Resolve Staffing to sell securities. Fox persuaded Steve Hillis to pay $135,000 and sign a Subscription Agreement in return for 90,000 shares of Resolve Staffing common stock. In 2007, Hillis and Resolve Staffing executed a Warrant Amendment and Exchange Agreement. The Warrant Amendment entitled the Hillises to buy another 90,000 shares of stock at a lower price than the first batch. These agreements each had a forum selection clause: the Subscription Agreement required venue in “the courts of the State of Ohio” and the Warrant Amendment required venue in the “State or Federal Courts serving the State of Ohio.”

In 2008, Resolve Staffing went out of business because of the involuntary foreclosure and sale of its assets by its primary lender. The Hillises lost their entire investment. They sued Resolve…