The merger will see Washington Mutual, the US's largest savings and loans providers, buy all outstanding shares in the company, paying $16 a share.
Commenting on the transaction, Kerry Killinger, Washington Mutual chairman and CEO, said that the deal ensured the expansion of his bank's services into the lucrative Californian market.
"Today's transaction strengthens our already solid position in the attractive California multifamily and small commercial real estate lendings markets," he said.
"It provides us additional opportunities [for] cross-sell to Commercial Capital's existing retail customer base, and we believe that there are significant operating efficiencies to be gained by bringing our two very similar operations together, with very low integration risk."
Stephen H. Gordon, chairman and CEO of Commercial Capital, added that he too believed that his bank's core lending and retail banking services would integrate smoothly with Washington Mutual.
With assets of more than $348 billion, Washington Mutual is one of the US's leading consumer and small business banks, and the new acquisition will see it strengthen its position in the country's retail banking sector.