Coal mining, it said, is responsible for thousands of deaths annually, while mountaintop removal mining and strip mining destroy entire ecosystems and communities.

RAN stopped short of calling for a boycott of the banks, but Rebecca Tarbottom, the group's finance campaign director, said Citi and Bank of America could expect "a ruckus in the streets," through protests and possible shareholder action.

Neither bank had any comment when asked by Reuters.

"Tell Citigroup and Bank of America to stop funding dirty coal projects and to redirect their resources and investments toward clean energy," the environmental group said in a conference call from its San Francisco headquarters. "Don't let your money be used to fund climate change.

"These banks MUST set real goals to reduce the 'financed emissions' from their investment portfolio and start funding the future," RAN said, accusing the pair of pledging to address global climate change while still funding the coal companies.

RAN said that rather than phase-out coal and reduce dangerous emissions, coal's proponents are pushing for the construction of more than 150 new coal-fired power plants throughout the United States.

"This new coal rush would add between 600 million and 1.1 billion tons of additional C02 emissions annually and negate nearly every other effort currently on the table to combat climate change," the group said.

RAN said Citi pledged in May to direct US$50 billion over the next 10 years to addressing global climate change through investments. "Financing for renewable energy, energy efficiency and improvements in energy infrastructure amount to US$31 billion spread across 10 years.

"While this may seem like a significant commitment, it amounts to less than 0.2 percent of the company's US$2.2 trillion in assets," the group said.

Citi underwrote more than US$38 billion for the energy industry in 2006, it said, while financing just one transaction for alternative energy. In 2006 Citi financed 200 times more money for "dirty energy" than it did for alternative energy.

Similarly, it said Bank of America pledged in March to support environmentally sustainable business and to address global climate change. "Unfortunately, CEO Ken Lewis' lofty rhetoric is at odds with his company's track record," RAN said. "In 2006, Bank of America spent nearly 100 times more money on dirty energy than it did supporting clean energy."

Bank of America's new climate pledge commits less than 0.2 percent of the company's US$1.5 trillion in assets to curbing climate change, it said.

"As long as Citi and Bank of America continue to fund dirty energy, they are holding back the resources needed for clean energy to flourish."

Coal, which is plentiful in the United States, is used to fuel approximately 50 percent of America's electricity generation. Environmentalists argue that future increased power demand could be met by alternative sources, such as wind or solar power.