Mesa Petroleum may sell more Unocal stock.

The Texas oil company, which still owns 12.7 million shares of the Los Angeles-based oil company that it tried unsuccessfully to buy last year, said that investment bankers are exploring the “appetite for the stock” and that it might sell all or part of its stake. Unocal said it has agreed to waive certain terms that would have made it more difficult for Mesa to sell its remaining holdings.