By Robb M. Stewart MELBOURNE--BHP Billiton Ltd. (BHP) said Friday its chief executive and the head of its petroleum division have elected to forgo their bonuses for last financial year after the company was forced to book a US$2.84 billion impairment charge against the value of U.S. shale gas assets bought just last year. Chairman Jacques Nasser said the board supports the actions of CEO Marius Kloppers and petroleum division CEO Mike Yeager, who have shifted the focus of the business from shale gas where prices have slumped in the U.S. to liquids-rich fields onshore U.S. The company said it also will take a US$450 million charge, also before tax, against the carrying value of its Nickel West assets in Australia as a result of margin deterioration. Write to Robb M. Stewart at robb.stewart@wsj.com Subscribe to WSJ: http://online.wsj.com?mod=djnwires
