The U.S. Climate Action Partnership has lost three heavyweights from its roster, including oil companies BP and ConocoPhillips and agriculture giant Caterpillar.

The trio of companies did not to renew their memberships, according to a USCAP statement.

“All three companies have provided invaluable assistance, expertise and significant commitments of time and resources in USCAP’s efforts to advance comprehensive climate and energy legislation,” the statement said. “We believe that U.S. action on energy and climate legislation in 2010 will preserve and create American jobs, secure our energy future and generate new investment in the global clean energy economy.”

The departures come after USCAP has taken a lower-profile lobbying approach after being praised last year by Members of Congress for its draft of climate change principles.

BP and ConocoPhillips’ exit leaves USCAP with only one oil company, Shell, as a member and shows a growing divide between energy sectors on how to address climate change issues.

BP’s Ronnie Chappell said the company left because it can be “a more effective advocate for a good climate change bill” as an individual company rather than as part of a group.

“What’s occurring is the policy debate is becoming more and more specific,” Chappell said. “As the policy proposals become more specific, it is easier for BP to play a role if it does so as BP as opposed to being a part of a larger coalition.”

The company still supports USCAP’s overall blueprint on climate change, according to Chappell.

Caterpillar’s Kate Kenny said the company is redirecting its resources toward “the commercialization of technologies that will promote and provide sustainable development and reduce carbon emissions.”

Caterpillar also recently announced its participation in the FutureGen Industrial Alliance, a partnership focused on building the world’s first coal-fired, low-emission power plant in Illinois.

Still, not all environmental groups are opposed to the companies’ departures.

“Clearly there is a very stark change of direction by some of the members in terms of legislative strategy going forward,” said Tyson Slocum of Public Citizen.

Erich Pica, head of Friends of the Earth, which is not a USCAP member, said the exits mean a “real discussion about what the planet needs” can begin “unhindered by some of the very polluters that are causing the global warming problem.”

This is the most recent dust-up of trade associations and coalition membership over climate change.

Last year, the U.S. Chamber of Commerce faced multiple defections, including Exelon Corp., Pacific Gas and Electric Co., Apple Inc. and others that were unhappy with the chamber’s vehement opposition to climate change legislation.