SAN FRANCISCO — Ryan Howard agreed to a $125 million, five-year contract extension through 2016 with the Philadelphia Phillies on Monday that includes a club option for 2017.

The 30-year-old slugging first baseman will make $20 million each in 2012 and 2013 and $25 million annually from 2014-16. The Phillies have a $23 million club option for 2017 with a $10 million buyout.

The $25 million guaranteed average salary in the extension will be baseball's second-highest behind Alex Rodriguez's $27.5 million average under a 10-year contract with the Yankees running through 2017.

Howard, the 2005 NL Rookie of the Year and '06 league MVP, is earning $19 million this season as part of a $54 million, three-year deal that pays him $20 million in 2011, the final season before he would've been eligible for free agency.

He signed that deal in February 2009, avoiding a potentially contentious arbitration hearing.

The two-time All-Star led the Phillies to two straight trips to the World Series, winning a championship in 2008.

Howard hit .279 with 45 homers and 141 RBIs last season and has three homers and 16 RBIs in 80 at-bats this April.

While he has put up monster numbers, averaging 49.5 homers and 143 RBIs over the past four years, he has averaged 191 strikeouts over that span.

Howard's deal, negotiated by agent Casey Close, could influence Derek Jeter's next deal with the Yankees and Albert Pujols' next contract with the St. Louis Cardinals.

Jeter, who also is represented by Close, is in the final season of a $189 million, 10-year contract.

Pujols is making $16 million this year, and St. Louis has a $16 million option for 2011 with a $5 million buyout. Of the 2011 salary, $4 million would be deferred without interest.

Earlier this season a rumor that the Phillies and Cardinals were discussing a swap of their superstar first basemen was quickly quashed.

Twins MVP catcher Joe Mauer signed a $184 million, eight-year extension this spring.