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 HP 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 HP.
GM says the move includes several multi-year services and software contracts with HP. GM Chief Information Officer Randy Mott worked at HP until joining GM in February.
The carmaker has announced plans for new information technology centers in Warren, Mich., and Austin, Texas.
Hewlett-Packard announced last monthby October 2014. The company told CBS MoneyWatch in a statement on Thursday that the 3,000 employees who are expected to transition to the automaker's staff will not affect HP's previously reported workforce reduction numbers.