Pettitte's agent, Randy Hendricks, confirmed to MLB.com on Wednesday that the 34-year-old left-hander had decided to pitch next season, ending the speculation that he might retire.
"He has decided to play," Hendricks said in an e-mail, confirming a report in The Associated Press.
Pettitte just completed a three-year, $31.5 million contract with Houston, going 37-26 with a 3.38 ERA for the Astros. Pettitte spent the first nine seasons of his career with the Yankees, who have extended a one-year, $15 million offer for him to return to the Bronx.
Hendricks said there was "no timetable" for Pettitte to make a decision on where he will play.
Pettitte is 186-104 with a 3.81 ERA in his career. He has won four World Series rings, all with New York, and appeared in three other Fall Classics, including one with Houston.
Mark Feinsand is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.