The Minnesota Vikings have signed center John Sullivan to a contract extension.

Sullivan, who became Minnesota's starting center in 2009, has appeared in 58 games, making 42 starts.

The Notre Dame product has helped the Vikings rank fourth in the league in rushing through 14 weeks of play.

"We are very excited about the future of John Sullivan," head coach Leslie Frazier said. "He has quickly become a leader among the offensive linemen. John is having an outstanding 2011 season and he is a big part of why our rushing attack is near the top in the NFL. We are thrilled about having John as a member of the Minnesota Vikings for years to come."