STANFORD, CA — BP, one of the largest oil and gas suppliers in the U.S., announced that it has reduced its greenhouse gas emissions by more than 9 million tons eight years ahead of target, and that it will peg net future emissions at this new, lower level despite plans to increase its oil and gas production by 5.5% per year.

In a speech at Stanford University, Lord Browne, chief executive officer, said that the company’s pledge, made four years ago, to cut emissions from its operations by 10% from 1990 levels by the year 2010 has already been achieved, and at no net cost to the company.