A multimillionaire financier, once engaged to marry President George W. Bush's former sister-in-law, is suing her for the return of an 11-carat ring that he says is worth $434,000.

Gerald Tsai Jr., 78, says he and Sharon Bush, 55, agreed to marry in October 2006 and he bought her the rectangular yellow diamond ring from Saks Fifth Avenue for $243,000. Tsai says the higher figure is the replacement value.

Bush's lawyer, David Berg, said Tuesday he was aware of the engagement and the ring — but not of the post-breakup lawsuit — and therefore had no comment.

The engagement was called off on Jan. 23, 2008, Tsai's papers say.

The lawsuit was filed Monday in Manhattan's state Supreme Court.