The national pension fund said Thursday it opposed a planned merger between SK Innovation Co. and its energy affiliate SK E and S Co., saying it could significantly undermine shareholder value.The National Pension Fund, a major shareholder of SK Innovation, made the decision, as SK Innovation is set to hold a shareholder meeting next week to vote on the planned merger.In a statement, the fund said there is "significant concern that a merger could hurt shareholder value."The fund is the second-largest shareholder of SK Innovation with a 6.2 percent stake.SK Innovation's biggest shareholder is SK Inc. with a 36 percent stake.Source: Yonhap News Agency