CHRYSLER <C> UNIT BUYS BENEFICIAL <BNL> UNIT Chrysler Corp said its Chrysler First Inc acquired a major portion of the commercial lending portfolio of Beneficial Business Credit Corp, a subsidiary of Beneficial Corp. It said the acquisition involves about 84 mln dlrs of net receivables. Chrysler First, a subsidiary of Chrysler Financial Corp, had receivables of 4.3 billion dlrs at the end of 1986.