BOSTON -- Boston Celtics co-owner Steve Pagliuca is considering a run for the U.S. Senate seat left vacant when Sen. Edward Kennedy succumbed to brain cancer, NewsCenter 5's Janet Wu has learned.

Pagliuca has hired Doug Rubin, Gov. Deval Patrick's former chief of staff, to run the campaign if he decides to run. Pagliuca will make a final decision this week on whether to enter the Democratic primary, Wu reported.

Pagliuca is a managing director of Bain Capital. He received a B.A. from Duke University and an M.B.A. from Harvard Business School.

Pagliuca, who is a registered Democrat, would join a growing field of candidates. On the Democratic side, Attorney General Martha Coakley announced that she is running for the seat.

Republicans state Sen. Scott Brown and Canton selectman Robert Burr are also in the race.