South Korea's two largest container carriers posted massive losses in the first quarter, hard hit by plummeting freight rates, the already-troubled firms said Monday.

 Both Hanjin Shipping Co. and Hyundai Merchant Marine Co. are struggling to stay afloat amid a drawn-out slump in the global industry. They have sought creditors' help to buy time for self-restructuring programs and avoid court receivership.

 Hanjin, the bigger shipper by revenue, said in a regulatory filing that it swung to a net loss of 261 billion won ($221 million) on a consolidated basis in the first three months of this year.

 Its revenue fell 25.1 percent on-year to 1.5 trillion won, as it swung to an operating loss of 115.7 trillion won.

 Hyundai also recorded 276.1 billion won in net loss, with sales declining 18 percent to 1.2 trillion won. Its operating loss also widened to 163 billion won, the company announced. (Yonhap)