Singapore's PACC Offshore Services Holdings (POSH) has filed a notice of arbitration against Mexico over the ending of OSV charters.

It alleges the government violated a treaty agreement between Mexico and Singapore over the promotion and reciprocal protection of investments.

The legal action is "in relation to certain of the group’s investments in Mexico, specifically those made to charter certain vessels for use by Pemex, Mexico’s state-owned oil company," it said.