09/11/2011 05:08 EDT | Updated 11/11/2011 05:12 EST

Cowboys sign Witten to extension: report

The Dallas Cowboys have signed veteran tight end Jason Witten to a contract extension, according to

Citing a source familiar with the deal, ESPN is reporting that the extension is worth $37 million US, with $19 million guaranteed.

Witten posted on his Twitter page early Sunday about the deal: "I am blessed to say that I will retire a cowboy!Thx to the jones family, and all the cowboy staff! True honor to put on the star!!"

Heading into this season, Witten has 617 receptions for 6967 yards and 36 touchdowns. He is second on the Cowboys' all-time in receptions and has missed just a single game during his eight seasons with the team.

The signing comes two days after the Cowboys agreed to a five-year contract extension with nose tackle Jay Ratliff.