Sept 22 (Reuters) - Entain’s shares jumped 10% to an all-time high on Wednesday after the gambling firm revealed a $22.4 billion takeover proposal from Boston-based DraftKings which was nearly double a bid it rejected from MGM this year. Shares rose to 24.9 pounds after the opening bell on UK’s bluechip index, below the 28 pounds per share that has been proposed by DraftKings. There has been speculation of another bid from MGM, with which Entain has a joint venture in the United States, after a $4.4 billion asset sale by the casino group last month.