For 40 years, federal law has prohibited broadcasters from accepting money or anything of value in exchange for playing songs on the radio without disclosing the practice to listeners.

But internal documents obtained by the Los Angeles Times indicate that several independent promoters keep detailed logs--called "banks"--listing the date a station airs a song followed by a dollar amount collected from the artist's label. The stations that add the most songs over the course of a year build the biggest banks and consequently earn the largest fees.

Like a bank account, there are debits and credits, deposits and withdrawals. The promoter makes "deposits" when the right songs are played and "withdrawals" for the station to receive payment in the form of cash, travel and tickets to events.

The documents show that each of the five major record companies--Vivendi Universal, Sony, Bertelsmann, AOL Time Warner and EMI Group--paid fees to an independent promoter associated with a Portland, Ore., radio station that played songs produced by their labels. Officials for these record companies declined to be interviewed.

Experts say the newly disclosed bank data could threaten the licenses of numerous stations.

"This document destroys the notion that the new payola is any different from the old payola," said Peter Hart, an analyst for the New York-based media watchdog group Fairness & Accuracy in Reporting.

"What you have here is a smoking gun. This document confirms suspicions that critics have long had about potential tit-for-tat arrangements between independent promoters and radio stations. An appropriate government investigation could blow this whole industry wide open."

Federal agents already are deep in a four-year probe of corruption in the radio business. Five executives from Latin music labels and radio stations have pleaded guilty to payola-related tax offenses. And last year, Clear Channel Communications, the nation's largest radio conglomerate, was fined for a payola violation involving a promotion that guaranteed airplay of a song by pop singer Bryan Adams in exchange for a series of free performances at concerts sponsored by its station.

Officials at the Federal Communications Commission and the Justice Department declined to comment on their investigations and on the bank arrangements.

Music Promotion Process Revealed

The world of music promotion and influence peddling is a murky one that is usually kept out of public view. Independent promoters dodge the tit-for-tat rules of payola by paying broadcasters annual fees they say are not tied to airplay of specific songs.

Practitioners of this $100-million-a-year trade--largely hidden under layers of arms-length alliances and thick legal opinions--seek to determine the songs that will reach the airwaves and climb the music industry charts. The newly obtained documents detail exactly how the process works, who is paid and how much, and how radio stations, promoters and the world's largest record companies say they keep their arrangements one step inside the law.

The documents include a sales pitch to prospective clients by Michele Clark Promotion, a Calabasas-based firm, that outlines a "sample bank." The company denies that such pacts cross the line into illegality.

"We aren't doing anything wrong here," Michele Clark said in an interview. "The support I get from labels has no effect whatsoever on the musical decisions of the program directors at my stations."

Besides, Clark said, the practice is widespread throughout the industry. "I didn't invent this thing. It's standard operating procedure in the promotion business. Every [independent promoter] in nearly every format uses it."

She added: "Every indie keeps internal accountings of what stations are worth. You base the value of a station on what you are able to bill on their behalf. Obviously, the more a radio format helps sell records, the higher the stakes will be for the labels--and the higher the budgets paid by indies to the stations involved."

Clark's firm caters to stations in the album adult alternative, or AAA, format--quiet rock music that accounts for only a sliver of U.S. music sales. The money funneled into AAA station banks is a pittance compared with what music conglomerates throw around in the industry's biggest radio formats, such as top 40, alternative and rock.

Indeed, record labels pay independent promoters as much as $4,000 per song to influence airplay at the nation's biggest broadcast outlets. And many labels have exclusive deals with promoters who operate under the same bank formula, promotion and label executives say.

Clark provides broadcasters with annual fees as high as $120,000 to defray expenses for contest giveaways, vacation fly-aways, concerts, conventions and other promotions, the documents show. The labels pay her about $1,000 per song that gets added to a playlist.