“Over time as we’ve watched the Chamber take its positions, it was just increasingly clear that we were on different paths,” said Brian Hertzog, spokesman for the Northern California utility.

PNM Resources, the electric utility company for New Mexico, has also pulled out of the Chamber.

“At PNM Resources, we see climate change as the most pressing environmental and economic issue of our time. Given that view, and a natural limit on both company time and resources, we have decided that we can be most productive by working with organizations that share our view on the need for thoughtful, reasonable climate-change legislation and want to push that agenda forward in Congress,” the company said in a statement.

It’s not just the utilities, though. Nike came out with a statement last week blasting the Chamber’s position on climate change. "Nike fundamentally disagrees with the U.S. Chamber of Commerce's position on climate change,” the company said in a release. The company stopped short of quitting the Chamber but it has resigned its seat on the Chamber's board.

Hertzog of PG&E said his company respects other organizations’ rights to continue to work within the Chamber.

“It’s really just a reflection of each company having to take a look at all of the issues that are in front of it,” he said. “For us, climate change is certainly one of, if not the, most important issues that we’re looking at the federal level. This is an issue that’s significant enough that a difference of opinion is enough for us to go in a different direction.”

President Obama has said he wants to cut greenhouse-gas emissions and return the United States to a position of world leadership in the fight against global warming. He is supporting legislation to that end and so are a number of businesses. Some 25 large companies—including DuPont, BP America, Ford Motor Company, and General Motors—have joined the United States Climate Action Partnership, a group focused on supporting cap-and-trade legislation.

Duke Energy, the nation’s second-largest burner of coal, and therefore one of the country’s biggest greenhouse-gas polluters, is a member of that coalition. The utility, which provides electricity in parts of the Southeast and the Midwest, isn’t going to quit the Chamber anytime soon. But it has left other organizations opposed to climate-change legislation.

In April, Duke CEO Jim Rogers said his company wouldn’t renew its membership in the National Association of Manufacturers after that group published a study saying the climate-change bill would cost 2.4 million jobs and add 50 percent to the cost of electricity.

“We want to invest in associations that are pulling in the same direction we are,” Rogers told Bloomberg at the time.

This summer, Duke abandoned its position as a member of the Clean Coal Coalition after learning that organization was going to be a dedicated opponent of capping greenhouse gasses.

“It became clear that there were certain members of the group that weren’t going to support climate legislation no matter how it was worded,” said Tom Williams, director of external relations for Duke Energy. That isn’t where his company is at, he said. “It’s not a perfect bill, but it came a long way,” he said of the pending legislation.