Moody's downgraded A.P. Moller-Maersk's credit rating on Tuesday, piling pressure on the world's biggest container shipper as it juggles a major restructuring with a multi-billion dollar acquisition of a German rival.
Moody's said the downgrade from Baa1 to Baa2 with a negative outlook "reflects Maersk's deteriorating credit profile".
The credit rating firm put the Danish shipping company under review in September, when it announced a split-up to focus on the shipping business and spin off its energy assets.
"(Maersk's) operations will be less diverse and potentially less protected from a downturn in its end markets," Moody's said in a statement.
Maersk's debt to operating profit ratio - a measure of a company's ability to cover its debt - climbed to 2.5 over the twelve months until the end of September, above Moody's downgrade benchmark of 2.25, the rating agency said.
Global container shipping is suffering its worst downturn caused by a faltering global economy and too many ships. The slump has prompted a series of mergers and alliances aimed at saving costs and pooling ships and routes.
Maersk said this month it had agreed to buy German rival Hamburg Süd, the world's seventh-largest container shipping line, at an undisclosed price.
The company is also trying to spin off its oil and gas business, but merger talks with DONG Energy, which has put its North Sea oil and gas assets up for sale, have stalled, sources told Reuters last week.
Last month, Standard & Poor's lowered the company's credit rating to BBB from BBB+ with a negative outlook.
The current ratings from both agencies are still considered investment grade, and Maersk stressed at its capital markets day last week it was committed to maintain that, even if it meant selling assets or cutting dividends.
(Reporting by Jacob Gronholt-Pedersen; editing by Susan Thomas)