Sources say the two sides will announce the signing of a three-year deal today at noon, a deal that will bring the Mariners about $5.5 million per season from Bonneville International, the company that owns KIRO.

For the past six seasons the Mariners have been heard on KOMO-AM/1000, part of a deal that brought the Mariners about $10 million per season. For 18 years before the switch in 2003, the Mariners had called KIRO home.

All of the game announcers, including lead broadcaster Dave Niehaus, who goes into the Hall of Fame in Cooperstown, N.Y., on Sunday and who has been the Mariner announcer since the franchise's first game in 1977, are expected to make the move to KIRO.

Those announcers are employees of the Mariners. Their contracts all are up at the end of the 2008 season, but that is, sources say, just coincidental with the end of the KOMO deal and Niehaus, Rick Rizzs, Dave Sims and Mike Blowers all are expected back for 2009.

The current pre- and post-game broadcasters -- including Shannon Drayer, KOMO's lead Mariner reporter and the station's Mariner blogger -- are employed by KOMO, so they could be looking for work if KIRO doesn't hire them.

Seattle's fortunes on the baseball field have taken a tumble since Fisher Communications, which owns KOMO, agreed to that deal, which was one of the most lucrative radio contracts in baseball when it was signed.

As a result, Fisher and KOMO suffered losses throughout the length of the contract. The onset of Internet broadcasts and the changes to the radio industry itself made the deal unworkable at the price Fisher was paying.

As part of the new radio landscape, radio stations don't have the exclusivity they once had over the audio of the game, which is available through satellite radio and through Major League Baseball on the Internet. Local radio stations are not allowed to stream the broadcasts they carry on the Internet.

Fisher dropped out of the running for a new contract last month, the previous contract having both helped the station define itself in the marketplace and prove very costly over the six-year run. The Mariners, however, have had three losing seasons in the last four years and have the worst record in the American League this year.

The Mariners had been on KIRO through two mostly lean decades before things turned around for the franchise in 1995, starting an almost decade-long upswing in the team's fortunes just as Fisher and KOMO swept in to stake its claim.

The deal with Fisher/KOMO set records for local radio and reportedly was, at the time, worth more than the local radio deals for the New York Yankees and Los Angeles Dodgers, teams located in much larger markets.

Although the Mariners will be getting just about 55 percent of what they had been used to, sources say there is language in the deal that will bring the club more depending on how things shake out over the course of the next three seasons.