By Andrea Shalal BERLIN (Reuters) - Turkey will likely hand off responsibility for NATO's counter-migration mission in the Aegean Sea, averting tensions with Greece, when it takes command of a broader maritime mission in the region next year, a top British general said on Wednesday. "Because of Turkish-Greek sensitivities ... the likelihood is that the Turkish commander will command a bit of the group, but there'll be a subset that is commanded by one of his deputies to deal with the Aegean," General Gordon Messenger, vice chief of defence staff for Britain, told Reuters. Diplomats have said that Turkey is unhappy about NATO ships moving about in waters that it and Greece have long contested and remains worried that Greece could gain the upper hand in a dispute about a group of Aegean islands.