Bellevue’s O’Brien Auto Group, the largest auto dealer in the Pacific Northwest, announced March 2 that it has purchased Bob Bridge Toyota Scion of Renton.

Michael P. O’Brien, of Mercer Island, is the owner of the  O’Brien Auto Group. While financial details were not made public, O’Brien confirmed that the deal formally closed this week, and the company has already begun operating as Toyota Scion of Renton.

The company also announced that it expects to retain all existing employees while adding more jobs in 2012.

Founded in 1986, O’Brien Auto Group is a privately held company that owns and operates 14 dealerships in Washington and Oregon.

The company employs more than 600 people and had annual sales exceeding $500 million in 2011.