The move is part of a larger GM strategy to have more control over the technology it uses in cars and to run its business.
The H-P employees already work on GM projects. GM says that making them full-time employees will hold costs steady and speed up the transformation of the company's computer-related work.
GM is hiring more software developers, opening technology centers and taking on work from outside firms like H-P.
GM says the move includes several multi-year services and software contracts with H-P. GM Chief Information Officer Randy Mott worked at H-P until joining GM in February.
The carmaker has announced plans for new information technology centers in Warren, Mich., and Austin, Texas.