The Environmental Protection Agency dodged senators' threat of a subpoena Thursday, gaining three more weeks to produce agency documents on a Bush administration proposal to relax pollution controls on some coal-burning power plants.

Sen. James M. Jeffords, I-Vt., said he was extending "good faith" to EPA Administrator Christie Whitman rather than ask the Senate Environment and Public Works Committee he chairs to compel her to testify July 11 or produce documents and e-mails sought.

After meetings late Wednesday, EPA promised to hand over more documents to the committee no later than July 3 and provide an additional delivery within the next three weeks, Jeffords said. But he added that even those productions wouldn't entirely fulfill his original request for information six months ago.

"Now that we have the agency's attention, it is my hope that we can obtain the remainder of our request without delay," said Jeffords. He said he would again pursue a subpoena at the next meeting in July if EPA doesn't turn over all the documents he wants relating to the Bush administration's June 13 proposal to revamp rules for the Clean Air Act's "New Source Review" program.

In a letter Thursday, EPA Associate Administrator Edward D. Krenik told Jeffords the administration worries about providing Congress with "pre-decisional documents" until after rule-making is finished. EPA plans to issue final rules by year's end, after the White House Office of Management and Budget reviews the proposal this summer

Krenik said the administration wants to meet the committee's oversight interests, but handing over documents too soon could "blur the separation of powers by affecting the free flow of internal discussions or otherwise influencing or interfering with that decision-making process."

In May, Krenik told Jeffords that EPA would provide about 700 pages of documents and spreadsheets, including some blacked-out material about pending enforcement cases against utilities. He said the agency withheld proposals made during confidential legal negotiations.

Congress has been sparring with the Bush administration to learn what information the administration has relied on in forming its energy and environmental policies. Earlier this year, the General Accounting Office, the investigative arm of Congress, sued Vice President Dick Cheney to obtain e-mails and other documents involved in Bush's energy policy proposals.

In May, Sen. Joseph Lieberman, D-Conn., issued the first congressional subpoenas to the administration for what he called stonewalling on demands for Enron Corp. records. On Thursday, he called Jeffords' threat to subpoena EPA "a simple request for very relevant information."

Jeffords hopes to obtain all documents in EPA's Washington and North Carolina offices about effects of the agency's decision on future emissions under the Clean Air Act, the projected impact on air quality and enforcement efforts and what role the utility industry played in shaping the proposed rules.