 Alliancebernstein L.P. decreased its holdings in shares of Columbia Banking System Inc NASDAQ:COLB by 4.6 during the 1st quarter, according to the company in its most recent 13F filing with the Securities Exchange Commission. The fund owned 116,566 shares of the financial services providers stock after selling 5,600 shares during the quarter. Alliancebernstein L.P. ... 