COLORADO SPRINGS, Colo. (AP) - A Justice Department official asked the energy industry for help in battling a record number of lawsuits, most of them environmental challenges of oil and gas drilling on public land.

About 7,100 cases are being litigated by the department's Environment and Natural Resources Division, said Thomas Sansonetti, an assistant attorney general of the Justice Department. More than two-thirds of the cases originated west of the Mississippi River, most of them in the Rockies.

"When these lawsuits come up, when they sue the federal agencies like EPA or BLM, intervene if possible," Sansonetti told executives at the Independent Petroleum Association of America conference Monday. "The fact is, we need help. Sometimes, two or three of our attorneys are matched up against entire law firms."

The department handled 3,200 cases during the Reagan administration and was litigating 4,500 in 1992 at the beginning of the Clinton administration.

Sansonetti said his agency employs 650 people, of which 417 are attorneys. Sansonetti said the Justice Department is a defendant in 55 percent of the lawsuits.

"The lawsuits make it harder to develop oil and gas in public lands," he said.

Mark Sexton, chief executive of the Denver-based gas company Evergreen Resources Inc., said the threat of litigation dissuaded him from drilling on public land. His company has focused on developing private and state property.

"The cost of attack is much less than the cost of defense; also, there is no penalty on baseless attacks," said Sexton, whose company recently agreed to a $2.1 billion buyout by Dallas-based Pioneer Natural Resources Co. "It's an abuse of the system; they use fuzzy science to attack the industry. And it costs the industry time and money to defend itself."

Suzanne Jones, regional director of The Wilderness Society's Denver office, said the Bush administration has targeted proposed wilderness areas, wildlife habitat and national monuments for development, leading to more lawsuits.

Pete Morton, a Wilderness Society economist, said the increase in lawsuits parallels the jump in drilling permits over the past two decades.

"To say that increasing appeals and litigation are hindering the Department of Justice from going after the bad guys is absolutely ludicrous," Morton said. "This administration has done more to undermine environmental protections than any other administration in recent history."