(Reuters) - British oil major BP said on Tuesday it had agreed to sell its Alaskan operations for $5.6 billion (4.6 billion pounds) to privately held oil and natural gas explorer Hilcorp Alaska as part of its divestment plans.BP said the deal, which includes interests in the giant Prudhoe Bay field and Trans Alaska Pipeline, is part of its plans to raise $10 billion over the next two years through asset sales to further strengthen its balance sheet.The deal with the Alaskan company comprises $4..