Morton passed a physical Wednesday. The guaranteed contract will pay him $4 million in 2014, and his salary will increase to $8 million in 2015 and 2016.
The Pirates also reached a deal with right-handed pitcher Edinson Volquez on a one-year contract for $5 million. The 30-year-old Volquez went 9-12 with a 5.71 ERA in 2013 while splitting time with the San Diego Padres and the Los Angeles Dodgers. The deal is pending a physical.
A club option for 2017 could increase the overall value of Morton's contract to $30 million.
If Morton is traded, the club option turns into a mutual option -- which gives the pitcher the ability to become a free agent before the 2017 season if he so chooses.
Morton, 30, is 30-49 with a 4.70 ERA in parts of six seasons with the Pirates and Atlanta Braves. Pittsburgh acquired Morton, outfielder Gorkys Hernandez and left-hander Jeff Locke from Atlanta for outfielder Nate McLouth in a trade in June 2009.
Morton's contract extension was reported earlier Wednesday by Yahoosports.com.
Volquez is the latest reclamation project signed by the Pirates. Volquez was an All-Star in 2008 when he went 17-6 for the Cincinnati. He has spent the last five years dealing with injury and other issues. He underwent Tommy John surgery in 2009 and served a 50-game suspension in 2010 for using performance-enhancing drugs.
Volquez gives the Pirates some rotation depth if the team cannot sign free agent A.J. Burnett, who is mulling retirement.
Information from The Associated Press was used in this report.