Free agent pitcher Danny Darwin, who led the National League in ERA last season for the Houston Astros, signed a four-year contract yesterday with the Boston Red Sox.

Terms of the contract were not disclosed. But Darwin's agent, Randy Hendricks, said the agreement was worth a possible $12.2 million.

Darwin, who got a $1 million bonus for signing, will total $6 million in 1991-92 and another $4.8 million in 1993-94, bringing the package to $11.8 million, Hendricks said.

Darwin, 35, also has a $100,000 incentive for games started or innings pitched each season. Hendricks said Darwin could earn another $400,000 in bonuses. Darwin, a 13-year veteran, was "deer hunting in South Texas" and could not be reached, Hendricks said.

"The Red Sox believe Darwin will give their pitching staff depth," team spokesman Josh Spofford said. He said Darwin likely is the last free agent the team will sign this winter.

Elsewhere, left-hander Fernando Valenzuela accepted arbitration with the Los Angeles Dodgers. He earned $2.2 million last season. His decision came hours before the midnight EST deadline for accepting or rejecting arbitration. Teammate Mickey Hatcher also agreed to arbitration.