In early 1990, Porsche engineers began working on what they had intended to be the third evolution of the 944, the S3. As they progressed with the development process, they realized that so many parts were being changed that they had produced an almost entirely new vehicle. Porsche consequently shifted development from the 944 S/S2 to the car that would replace the 944 entirely, the 968. The 944's final year of production was 1991 with over 200,000 cars built and were sold. In 1992 the 968 debuted and was sold alongside the 928 through 1995, when both water-cooled front engine models were discontinued.
Source: Wikipedia, 2013