Sen. John McCain (R-Ariz.) yesterday released a sheaf of documents detailing his intervention with federal regulators on behalf of 15 campaign donors, importuning various agencies for contributors ranging from local telephone companies to cable television broadcasters to airline carriers.

The letters--coming on the heels of earlier reports about McCain's efforts for a broadcast network that lent McCain its corporate jet for use in his presidential campaign--could add to the difficulties of a candidate who has billed his White House campaign as a crusade to end the practice of campaign donations buying action on Capitol Hill.

Yesterday, McCain insisted that he had appropriately intervened to help "the consumer" rather than offering special favors for his contributors, which included telephone company BellSouth, cable giant TCI, and America West airlines. And his aides emphasized that the vast majority of the 500 letters they made available to reporters yesterday were written not for big donors but for individuals and companies that had never given the senator a dime.

The deluge of paper on a Saturday afternoon in football playoff season was designed to help the McCain campaign get out in front of the controversy rather than enduring a steady drip of stories in the weeks before the New Hampshire primary on which his maverick presidential candidacy rides.

Since Wednesday, McCain has been answering questions about his ties to Paxson Communications, a family broadcasting network whose lobbyist enlisted McCain's help in getting the federal regulators to act on its acquisition of a Pittsburgh station.

The letters--produced by the Senate Commerce, Science and Transportation Committee chaired by McCain--were written by him to an alphabet soup of federal agencies over the last several years. Generally, the letters simply urged speeded-up action rather than any specific outcome, a more circumspect approach than the demands made by some other legislators in their dealings with federal agencies.

For another candidate, such missives might be greeted with a collective yawn--committee chairmen inevitably find their campaigns bankrolled by the corporate interests whose businesses they oversee. But for McCain, the letters underscore the particularly combustible mixture of his presidential candidacy, his emphasis on campaign finance reform, and his powerful role as Commerce Committee chairman, with jurisdiction over 80 percent of the nation's business.

Underscoring McCain's dilemma, one congressional aide familiar with his committee said, "He wants to become president to get rid of the special interests, but he needs the special interests to help him do it."

The letters released yesterday covered the landscape of the Commerce Committee's activities.

In 1998 McCain wrote two letters to the Federal Communications Commission on behalf of BellSouth, which was seeking permission to enter the long-distance business in Louisiana. Under the law, it could do so only after showing it faced robust competition, but the FCC refused to count wireless phone companies as BellSouth competitors as the company wanted.

"We are very concerned" about the FCC's reading of the law, McCain and Sen. Sam Brownback (R-Kan.) said in a March 1998 letter. Six months later, McCain weighed in again. "I encourage you to give serious consideration" to whether wireless companies should be considered valid competitors, he wrote.

BellSouth has given McCain's senatorial and presidential campaigns $60,000, ranking as one of his largest donors over a political career. That includes $22,000 raised from BellSouth employees at a McCain event in Atlanta that the company organized last spring and that brought in an additional $15,000 from executives at other firms. McCain has also flown aboard the company's corporate jet, a crucial benefit for a campaign that cannot afford to charter its own plane.

McCain aides said yesterday that Commerce Committee staff members who draft the letters--most of which aren't even read by McCain--have no knowledge of his campaign's fund-raising. Meanwhile, they said, the finance team knows little about what actions the committee is taking.

"The senator in his letters never advocates one action or another," said Mark Buse, the panel's staff director. "We go overboard on all our letters that way."

That was the case last spring, Buse said, when McCain wrote FCC Chairman William E. Kennard two letters raising questions about the FCC staff's handling of the then-pending merger of two local Bell telephone companies that had contributed to the senator's campaign: SBC and Ameritech.

"We are extremely troubled" by the FCC's delays in reaching a conclusion as to whether the proposed merger stifles competition, McCain said in an April 1999 letter. "We find it disconcerting in the extreme," he said, that the agency was applying a tougher standard than in previous transactions. In another letter a month later, McCain criticized the commission for allowing a staff member to attack the merger.

Ameritech and its employees have given McCain's campaign $12,000, and its chief executive officer, Richard C. Notebaert, was one of four co-hosts of a McCain event that raised $88,000.

McCain also wrote to Kennard in August, arguing an arcane point about satellite regulation that also is favored by satellite communications firm Echostar, which has contributed $18,000 to his campaign and hosted a fund-raiser.

Last spring McCain wrote a letter to the FCC arguing in favor of the position of another contributor, Global Crossing, which is building undersea telecommunications cables around the world. But in this case, McCain also was arguing against the stance taken by yet another contributor, AT&T.

McCain's biggest all-time campaign contributor is local phone company US West, which has given him $107,500 over the years. Its CEO, Sol Trujillo, also is one of his current campaign's biggest fund-raisers.

But the papers released yesterday apparently did not show McCain directly intervening for the company. In fact, the senator recently angered the company by criticizing an Arizona state decision that was highly advantageous to US West in the costs it could pass on to competitors for using its networks.

Commerce Committee aide Buse also detailed times McCain has angered industries that support him. For example, he said, McCain recently called for a Federal Trade Commission investigation of slot machines that feature cartoon characters, prompting an angry call from gambling lobbyist Frank J. Fahrenkopf Jr. "in high dudgeon" over McCain's intervention. The gambling industry has been a leading contributor to McCain, who has collected more than $100,000 from gambling interests since 1993, according to the Center for Public Integrity.

Campaigning in South Carolina yesterday, McCain declared that his positions were based "on one fundamental principle and that is to try to protect the consumer." And, he said, "Take a look at what other congressmen and senators do. What is the standard and am I acting in higher standard? I think so."

Campaigning with McCain yesterday, Sen. Fred Thompson (R-Tenn.), who led hearings into 1996 fund-raising abuses, came to his defense. "All of us are always asking for prompt consideration of things," he said. "Because of the massive amount of money in our politics now, we run an increased risk of matching all these requests we make with a contribution we got."

Staff writer Dana Milbank in South Carolina contributed to this report.