Exxon Corp. v. Breezevale Ltd., 82 S.W.3d 429, 438 (Tex.App. --- Dallas 2002, pet. den.).

To invoke the application of promissory estoppel where there is an oral promise to sign an agreement, as in this case, the agreement that is the subject of the promise must comply with the statute of frauds. ... That is, the agreement must be in writing at the time of the oral promise to sign it.

Sullivan v. Leor Energy LLC, --- F.3d ----, 2010 WL 909109, *4 (5th Cir. 2010)

Under Texas law, promissory estoppel requires that “the agreement that is the subject of the promise must comply with the statute of frauds. That is, the agreement must be in writing at the time of the oral promise to sign it.” FN22

FN22.Breezevale Ltd., 82 S.W.3d at 438.