Ward, the Steelers' all-time leader in receptions (1,000), receiving yards (12,083) and receiving touchdowns (85), will be let go before the start of the 2012 season, Rooney said in a statement posted on the team's Web site.
"Hines has been an integral part of our success since we drafted him in 1998 and we will forever be grateful for what he has helped us achieve," the owner said. "He has meant so much to this organization, both on and off the field, and we appreciate his efforts over the past 14 years."
Ward, who will turn 36 March 8, won two Super Bowls with Pittsburgh and last year became the eighth player in NFL history to rack up 1,000 career receptions.
"This isn't how I wanted this chapter of my career to end," Ward said in an issued statement. "I did everything in my power to remain a Steeler and finish what I started here 14 years ago.
"I want to thank the organization, my teammates and coaches and everyone who made my run as a Steeler the best years of my life."