Japan's top three shipping companies on Thursday reported record earnings for the first half, enjoying a historic boom in the global sea freight market, driven by China's red-hot economic growth.

Nippon Yusen K.K., Mitsui O.S.K. Lines Ltd. and Kawasaki Kisen Kaisha Ltd. also forecast record profits for the full year, expecting continued robust cargo traffic to more than offset rising fuel prices and a stronger yen.

Nippon Yusen, the largest shipping firm, said its net profit jumped 40 percent to 29.77 billion yen for the April-September period, with revenue up 13 percent to 768.18 billion yen.