The invention is an adhesive composition comprising a) one or more silane functional prepolymers comprising a polyether or a polyolefin backbone and silane moieties capable of silanol condensation; b) one or more isocyanate functional prepolymers comprising a polyether backbone and isocyanate moieties; c) one or more organotin compounds or titanate or zirconate compounds having one or more ligands comprising a hydrocarbyl phosphate ester or a hydrocarbyl sulfonate ester, or a mixture thereof; d) a tertiary amine or an anhydrous strong organic acid which is miscible with the polymer and enhances the bonding of the adhesive to a coated unprimed substrate. In one embodiment, the invention is a method of bonding two or more substrates together using the adhesive compositions of this invention. The process comprises applying an adhesive as described herein to one or more of the substrates; contacting the one or more substrates with the adhesive disposed between the substrates; and allowing the adhesive to cure.