Singapore's Ezion Holdings has blamed "prolonged weakness" in OSV markets for the loan default experienced by its joint venture POSH Terasea.

Its partner in the company, PACC Offshore Services Holdings (POSH), revealed the default involving an unnamed lender this week, and said it faced an impairment of $42m.

Ezion has an effective 25% stake through its share in POSH Terasea co-owner Terasea, which also involves Seabridge Marine Services.