Exxon Mobil, the world's largest publicly traded oil company, is making a $29 billion bet that pressure to curb climate change will mean natural gas - cleaner than coal and suddenly much easier to reach - will become a crucial source of U.S. power. Exxon agreed to buy XTO Energy in an all-stock deal at a 25 percent premium, showing how eagerly a company that is among the most conservative in a conservative industry is jumping into the natural gas market. The deal announced Monday was also the largest for the U.S. energy sector in at least four years and Exxon's biggest acquisition since it bought Mobil Corp. for $75 billion in 1999.

- Associated Press