Mitsui OSK Lines (MOL) shares rallied this week as analysts gave the giant Japanese shipping conglomerate positive ratings — but, in the background, a ship casualty involving a related company dating back more than seven years is casting a shadow over its future earnings.

The loss of the Ocean Victory at Kashima Port in 2006, for which a UK court ruled that subsidiary Daiichi Chuo Kisen must pay $166m in compensation, interests and costs, is being cited in Tokyo financial circles as a factor that may eventually have significant repercussions for the parent company’s balance sheet.

But