UPDATE (Friday, 10:15 a.m.) -- The 49ers confirmed Anthony Davis' five-year extension in a press release.
"Anthony is a very hard working, dedicated and talented young player who has earned the respect of our entire organization," said 49ers General Manager Trent Baalke. "Having already made significant strides early in his career, Anthony is just beginning to realize his full potential. We look forward to watching him achieve even greater results in the years to come."
The 49ers reached terms early Friday morning on their first big contract of the offseason. Keeping with their philosophy of retaining the nucleus of the team, the lucrative deal was with one of their own players.
Right tackle Anthony Davis agreed to a five-year contract extension through the 2019 season that includes $37.295 million in new money with $17 million in guarantees, an NFL source confirmed. Pro Football Talk first reported the deal, which was negotiated by agent Drew Rosenhaus and 49ers chief operating officer Paraag Marathe.
Davis becomes the first of the potential big-money contract extensions the 49ers hope to extend to key components of the team. Quarterback Colin Kaepernick, outside linebacker Aldon Smith, wide receiver Michael Crabtree and guard Mike Iupati all have contracts that expire after the 2014 season.
Davis' previous rookie contract ran through the 2014 season and included nearly $16 million guaranteed.
Under rules in the new collective bargaining agreement, Kaepernick and Smith are not eligible to sign contract extensions until after the 2013 season.
Davis, 23, has started every game of his three-year professional career after the club traded up two spots to select him with the No. 11 overall pick in the 2010 draft. He enjoyed his best season in 2012, when he was named as an NFC Pro Bowl alternate. The entire 49ers' offensive line started every game together last season, helping.the 49ers repeat as NFC West champions and reach Super Bowl XLVII, which they lost 34-31 to the Baltimore Ravens.