Seattle, WA (Sports Network) - The Seattle Mariners signed pitcher Hisashi Iwakuma to a contract extension through the 2014 season with an option for 2015.

The 31-year-old right-hander went 9-5 with two saves and a 3.16 ERA overall in 30 appearances, including 8-4, 2.65 ERA in 16 starts last season, his first in the majors. His ERA as a starter set a rookie club record.

"Kuma really helped solidify our rotation in the second half of the season," manager Eric Wedge said. "He is a competitor on the mound and did a great job for us. He got stronger with each start during the season and gained confidence. I am looking forward to seeing him on the field ready to work when we start spring training in Peoria."

Before coming to the Mariners, Iwakuma notched a 107-69 record in 226 career games with Kintetsu (2001-04) and Rakuten (2005-2011) in the Japan League.

11/02 23:31:24 ET