Cosalt, the struggling provider of safety equipment to the oil industry, confirmed this morning it has received an approach for its marine business."These discussions are not sufficiently advanced for there to be any certainty that a transaction would be concluded or as to the price and other terms upon which it would be concluded," the firm said in a brief statement.Last month, the company admitted an internal review had uncovered evidence of a stock shortfall of up to £4m linked to a series of doubtful transactions involving a supplier.In September, the maker of things like lifejackets, First Aid gear and fire extinguishers, suspended Calum Melville, head of its offshore division. Melville joined Cosalt when it bought GTC Group, a supplier of lifting equipment to the oil and gas industry he owned with his brother Stuart, in 2008 for £30m.