The reported posting fee for Japanese pitching sensation Yu Darvish continues to rise.

The top sealed bid, said to be submitted by the Toronto Blue Jays, surpassed the record $51.1 million US fee that the Boston Red Sox paid to negotiate a contract with Daisuke Matsuzaka in 2006, Japanese league officials told

Earlier this week, media outlets in the U.S. and Japan pegged the winning bid in the $40 million to $48 million range. Darvish’s team, the Hokkaido Nippon Ham Fighters, is expected to accept the bid before a 5 p.m. ET deadline on Dec. 20.

Besides the Blue Jays, the Texas Rangers, New York Yankees and Chicago Cubs are believed to have submitted bids.

If the bid is accepted, MLB will announce the team that won the rights, and that club will have 30 days to agree to a contract.

The posting fee will be paid only if an agreement is reached with Darvish's agents, Arn Tellem and Don Nomura.

If no deal is reached, Darvish returns to the Fighters for another season and the Fighters must return the posting fee to the major league club.

The six-foot-five hurler had an 18-6 record with a 1.44 earned-run average and a league-leading 276 strikeouts in 2011.

Darvish, who reportedly throws seven pitches including two- and four-seam fastballs as well as a cut fastball and a bevy of off-speed stuff, pitched in the 2008 Beijing Olympics and first gained notoriety in the U.S. in 2009 when he led Japan to a World Baseball Classic title.