EXXON <XON> SOUTH AFRICAN UNIT ACQUIRED BY ZENEX <Zenex Oil Pty Ltd> said it acquired the interests of Esso South Africa, the local subsidiary of Exxon Corp <XON), and will use up to 20 mln rand in profits to finance educational and social programs. The profit scheme will begin after Zenex has paid Exxon an undisclosed purchase price for Esso, Zenex chairman John Truscott said in a statement. The acquisition follows the Exxon withdrawal from South Africa announced last December.