The Dallas Cowboys and franchise quarterback Tony Romo have reached an agreement on a 6-year extension worth $108 million, league sources told ESPN NFL Insider Adam Schefter. The deal makes Romo the highest-paid player in Cowboys franchise history.

Cowboys chief operating officer Stephen Jones and one of Romo's agents, CAA's R.J. Gonser, spent recent days negotiating a deal that contains more guaranteed montey than the six-year, $120.6 million contract that made Ravens' quarterback Joe Flacco the highest played player in NFL history, sources said. By negotiating a new deal with Romo, the Cowboys have lowered his salary-cap number and free up money to sign other players to improve their defense.

Dallas didn't want Romo to enter into the last year of his contract and become an unrestricted free agent after the season. Both sides have had on-and-off talks about working out a new deal for most of March.