OAKLAND -- An already wealthy A's pitching staff may be getting even richer.

The club won negotiating rights to right-handed Japanese pitcher Hisashi Iwakuma on Monday and now has 30 days to come to terms with him on a contract.

"The Oakland A's are excited to have had our bid for Hisashi Iwakuma accepted by the Rakuten Golden Eagles," the team said in a statement. "Out of respect for the posting process and for Mr. Iwakuma and his representative, we will not have any comment until the 30-day negotiation period comes to an end."

The A's were said to be one of three teams, alongside American League West rivals Texas and Seattle, who submitted bids for Iwakuma to the Golden Eagles of Japan's Pacific League last week. The Golden Eagles were expected to make more than $16 million on the posting, though Oakland's exact bid was unknown.

If signed to a contract, the 29-year-old Iwakuma would join an A's pitching staff that already boasts Trevor Cahill, Brett Anderson, Gio Gonzalez and Dallas Braden -- a group deemed by some to be among the best young rotations in the American League.

The thinking in Oakland is that, with an added bat or two this winter, the A's could be serious contenders in 2011. By landing Iwakuma, Oakland would essentially receive extra trade bait, as the Japanese pitcher -- along with righty Vin Mazzaro -- could be used to get that needed lineup power.

Iwakuma posted a 10-9 record and 2.82 ERA and averaged 6.9 strikeouts and 1.6 walks per nine innings this season. He has compiled an ERA of 3.40 or lower in each of the past four seasons.

He had 21 wins and a 1.87 ERA in 28 starts in 2008. A 10-year veteran, he pitched for Japan in the World Baseball Classic in 2009, earning a spot on the All-Tournament Team while helping his homeland to the title. He was the starting pitcher for Japan in the Classic's decisive victory over Korea.