Strikeforce released its middleweight champion, Jake Shields , from his contract with the organization on Wednesday, according to an industry source with direct knowledge of the negotiations.The 31-year-old Shields had been in a final-phase “matching period” of his recently completed contract with the San Jose, Calif.-based promotion, which allowed him to receive bids from other organizations, including the UFC, that Strikeforce could review and match in order to keep his services. However, the source said Strikeforce waived that contractual right in its final 2-3 weeks and opted to release the Cesar Gracie fighter altogether before the period expired.Strikeforce CEO Scott Coker confirmed to Sherdog.com that the promotion informed Jack Shields, the fighter’s manager and father, of the release on Wednesday. Coker would not comment further on the decision.“In the conversation we had today, they said they felt that Jake was leaning towards the UFC. Honestly, we were talking to them with an open mind, though Jake wants to fight the best,” said the elder Shields. “Between Strikeforce and EliteXC, Jake had the chance to fight on Showtime and CBS four or five times against some top fighters like Dan Henderson and Robbie Lawler . Strikeforce gave him great opportunities and exposure. They’ve been nothing but great for Jake.”Shields, who successfully defended his title against former Pride Fighting Championships champion and UFC middleweight Henderson on April 17 in Nashville, Tenn., opted to not negotiate a renewal contract with Strikeforce prior to the bout. The fighter’s contract, which was originally drawn up by Pro Elite and purchased by Strikeforce after the short-lived fight organization went bankrupt in October 2008, also did not contain a standard “champion’s clause,” which could have placed stipulations on Shields’ renegotiations while he remained a titleholder.Prior to news of the release, Jack Shields told Sherdog.com that he submitted the fighter’s asking price to the UFC on Wednesday and was awaiting an initial bid from the rival promotion to pass onto Strikeforce for review. The elder Shields said he submitted figures for a series of bouts he thought requisite if his son fought the top contenders in both the UFC’s welterweight and middleweight divisions.Shields said his son would like to debut as a UFC middleweight, possibly against champion Anderson Silva , as welterweight champion Georges St. Pierre will be tied up with “The Ultimate Fighter” reality TV series and a pending bout with rival coach Josh Koscheck later this year.“We didn’t come to agreement with Strikeforce, but Jake’s excited to challenge himself against the likes of Anderson Silva and others in the UFC,” said Shields.In recent weeks, Strikeforce’s Coker had said the promotion had initial plans to hold a four-, eight-, or even 16-man tournament to crown a new champion if Shields vacated.