A modified factor VIIa is provided. The modified factor has increased amidolytic activity in the absence of T.F. and a higher affinity for T.F. when compared to the native factor VIIa but does not have substantially altered proteolytic activity when bound to T.F. Nucleic acid molecules that encode the factor, expression vectors that contain the nucleic acid molecules, cells that contain the nucleic acid molecules, and cells transformed with the expression vector are also provided. In a preferred embodiment, the modified factor is a human factor VIIa.