HAVANA (AP) — The third exploratory well drilled this year in deep waters off Cuba has come up a bust, authorities announced Friday, in yet another blow to the island’s hopes of a petroleum windfall that could boost its sagging economy.

Work on the well in the Gulf of Mexico off the western tip of Cuba, sunk by key ally Venezuela’s state oil company PDVSA, concluded Oct. 26, according to a notice published by Communist Party newspaper Granma.