The complicated sale, ongoing for nearly a year, is expected to close within the next several weeks.
The sale allows Dan Rooney, now the U.S. ambassador to Ireland, and Art II to control 30 percent of the team's shares, as required of a principal owner under NFL rules.
Dan Rooney and his son are taking on about $250 million in debt to complete the takeover, with their shares used as collateral for a loan arranged by PNC Bank.
Previously, the five sons of Steelers founder Art Rooney Sr. -- Dan, Pat, John, Art Jr. and Tim -- each owned a 16 percent stake in the team.
Tim and Pat Rooney are selling their entire 16 percent stakes, while Art Jr. and John Rooney are selling about half of theirs. Tim Rooney and Pat Rooney run the family's race track business, which now involves gambling operations not permitted by NFL rules.
To help them complete the transaction, Dan Rooney and Art II added additional investors, including movie producer Thomas Tull; James Haslam III, the president of truck-stop operator Pilot, and the Paul family of Pittsburgh.
Art Rooney II is running the Steelers while his father is in Ireland, although he has largely done so since becoming team president six years ago.
Copyright 2009 by The Associated Press