INDIANAPOLIS (AP) _ General Motors Corp. announced plans today to sell its Allison Gas Turbine division to a group led by a New York investment firm that also includes division management.

Clayton Dubilier & Rice said it had agreed to purchase the aircraft engine maker for an undisclosed amount.

Allison has three facilities in Indianapolis and one in Evansville, with a total work force of about 4,700. It is a separate division from its sister company, Allison Transmission, which also is being sold by GM.

GM announced last year it would sell Gas Turbine and other non-automotive units and shift its attention to sagging car sales. GM owned both Allison companies since 1929.

Officials said they did not expect major changes in management or the work force at the new company, which will be called Allison Engine.

''I would assume their level of employment would remain the same as (if) they had stayed with GM,'' said Bill Hogland, GM's executive vice president for corporate affairs.

Officials gave few specific details at a news conference today of the management partners involved in the Gas Turbine sale, saying they were still negotiating final terms.

The new management will honor the current United Auto Workers contract currently covering the majority of Gas Turbine employees, said Donald Gogel, a general partner of CDR. However, terms of any future contracts will be negotiated with the local UAW instead of on a national level.

''I'm looking forward to it. At first I didn't like it, but I guess I'm excited about it,'' said Bob Woodcock, chairman of the United Auto Workers bargaining committee for Local 933, which represents 2,800 to 2,900 employees.

In the past, Gas Turbine has relied heavily on the defense industry, selling engines used in transport planes and helicopters. In the wake of Defense Department cuts, however, it has relied on commercial business, which also has been weak.