CANADIAN NATURAL RESOURCES TO SELL STAKE <Canadian Natural Resources Ltd> said it agreed in principle to sell 80 pct of its working interest in certain producing and non-producing natural gas properties located in southwestern Saskatchewan. The transaction is expected to close on April 1, 1987, the company said. It did not identify the buyer nor give the selling price. Proceeds will be used to satisfy a February 1987 repayment demand by one of the company's lenders. Any excess proceeds will be added to working capital, the company said.