SEATTLE (AP) - The Seattle Mariners have agreed to a four-year contract with free-agent starting pitcher Carlos Silva.

Terms were not immediately known, though the deal is believed to be worth approximately $44 million.

The 28-year-old right-hander, who was to be introduced to his new city in a news conference Thursday afternoon, was 13-14 last season for the Minnesota Twins with a 4.19 ERA - better than every Mariners starter other than hard-throwing Felix Hernandez.

The Mariners like that Silva pitches deep into games, generally stays low in the strike zone with a sharp sinker and doesn't walk many. All three issues hurt Seattle in its late-season collapse from surprise contention in 2007. Silva walked just 36 batters in 202 innings last season.

He joins a Seattle rotation that includes Hernandez, Miguel Batista and Jarrod Washburn.

One starting spot remains open. The Mariners are pursuing a trade for Baltimore's Erik Bedard that would likely cost top outfield prospect Adam Jones, among others. Bedard is not only good - 13-5 last season and 15-11 the year before for two bad Orioles teams - his contract status is attractive. The Canadian left-hander is still eligible for arbitration and under team control for two more seasons.

"We feel that signing Carlos addresses one of our main needs, adding a quality arm to the starting rotation," general manager Bill Bavasi said. "Our goal heading into the off-season was to identify the best available pitcher on the free agent market and we feel we got the best one."