AOL, Yahoo and RealNetworks must pay an estimated $100 million in broadcasting fees to music publishers and songwriters, the U.S. District Court ruled, after rejecting the three broadcasters' proposal to pay the fees based on the revenues of music use on their websites.

Instead, the judge established a formula that also includes the total revenue of the business unit, the hours of music streamed and the overall use on the site. What this means is that AOL, Yahoo and RealNetworks will have to pay fees that go back to several years ago.

The American Society of Composers, Authors and Publishers (ASCAP) issued a statement saying that “the ruling is a major step toward a proper valuation of the music contributions of songwriters, composers and publishers to these types of online businesses – many of which have built much of their success on the foundation of the creative works of others.”

The terms of the ruling and the new formula of the fees music broadcasters have to pay are still not very clear and could be interpreted in various ways. The 153-page decision stated that the ruling includes all licensing fees from July 2002 to December 2009.

The online music business has grown considerably over the past years, and as the business start generating more, the music publishers and songwriters want more.

John Potter, executive director of Digital Music Association (DiMA), said in a statement following the ruling: “DiMA agrees that Internet portals and multi-faceted online services ahould pay fair royalties to songwriters and music publishers. We are disappointed, however, that the court rules that online services’ royalties should be base on service-wide revenue, not simply on revenue attributable to music usage.”