More than a thousand Utahns have signed a petition asking billionaire Warren Buffett to cut Rocky Mountain Power's dependence on coal-generated electricity.

A two-page letter and a petition carrying almost 1,600 signatures was sent to Buffett last week, said Alexander H. Lofft, who collected the signatures on his Web site.

Buffett is chief executive officer of Berkshire Hathaway Inc., a Nebraska company with interests in insurance, finance, manufactur- ing, retail, services and energy.

His empire includes the Mid-American Holding Corp., which owns PacifiCorp, the parent company of Rocky Mountain Power.

Lofft, a Park City real estate broker, said he thought Buffett should know that Utahns want cleaner energy for reasons related to climate, health and economics.

"I thought it would grab people's attention," said Lofft. "I thought it would get a response of some kind, if not from himself, from someone else in his organization."

Lofft started collecting petition signatures in February and has met with executives at both Mid-American and Rocky Mountain Power

He said he doesn't want to shut down all coal plants but hopes the petition will encourage the company to move toward energy sources that cause less pollution and contribute less to global warming.

Rocky Mountain Power is already working in that direction, company spokesman Dave Eskelsen said.

"I don't know what kind of impact the petition might have," he said, noting that Buffett is generally not involved in day-to-day operations of his companies.

Mid-American is a leader in wind and geothermal energy, but "we still see coal as part of our future," Eskelsen said.