Moody's Investors Service Inc. said Tuesday it has assigned a Baa2 issuer rating with a stable outlook to Nippon Yusen K.K.

"The rating reflects NYK's position as the leading shipping company in Japan and its core membership in the Mitsubishi Group," the U.S. credit-rating agency said.

The agency said NYK is active in all three shipping areas -- container liners, tramp ships and oil/LNG tankers -- and that the company's diversified shipping operations should help stabilize earnings during periods of market softness.

The rating also reflects the company's highly leveraged financial position and high fixed-cost structure requiring a large amount of investment to remain competitive, the agency said.