FRANKFURT (Reuters) - Deutsche Bank does not have to pay former investors in its retail subsidiary Postbank a higher compensation than offered in its 2010 tender offer, a German court ruled on Wednesday. The Cologne Higher Regional Court dismissed the suit by former Postbank shareholders, who had accepted the bid worth 25 euros ($30.50) a share, but asked for a significant bump, arguing that Deutsche Bank had bought shares earlier at a higher price. The claimants had argued that Deutsche Bank effectively took control of Postbank in 2008 when it bought a stake of just under 30% at a much higher price than 25 euros, which the court ruled was not the case. The investors, which include Effecten Spiegel AG, had sued Deutsche Bank for 740 million euros ($903 million) in additional compensation. They can appeal the ruling at the Federal Supreme Court. ($1 = 0.8198 euros)