Confirming speculation that surfaced last summer, the New York investment firm of Joseph Littlejohn & Levy is buying the fourInterior and Lighting plants, creating a company called Peregrine Inc. to run it and names Edward J. Gulda, a former CEO of Varity Kelsey-Hayes, as Peregrine's CEO. The plants are located in Oshawa and Windsor, Ont., and Livonia and Flint, MI. They employ about 4,000 workers who will be covered by the recently ratified agreement between GM and the UAW. They produce such interior trim items as window regulators, stampings and door panels. As part of the sales agreement, Peregrine will retain most of the GM supply business previously done by the Delphi plants, which were not among 12 to 15 "troubled" plants Delphi management has deemed non-competitive.