CPC INTERNATIONAL <CPC> SELLS SOUTH AFRICAN UNIT CPC International Inc said it has completed the sale of its South African subsidiary Robertsons Pty Ltd to a consortium of European and South African investors for an undisclosed amount in excess of book value due to the increasing difficulty of operating there. It said the operation accounted for less than two pct of worldwide sales of 4.5 billion dlrs in 1986. The company said small royalties expected to result from use of CPC trademarks by the new owners will be utilized for social programs in south Africa." It said no significant impact on earnings is expected from the sale.