LONDON (Bloomberg) — The European Union began an antitrust probe into marine-insurance agreements among groups of ship owners, saying it would check if they unfairly shut commercial insurers out of the market.

Most ship owners belong to 13 so-called protection and indemnity clubs. Based on tonnage, they jointly insure about 93 percent of the world's ocean-going ships.

The European Commission, the executive body for the 27- nation EU, said yesterday it needs to determine if these agreements lessen competition between the clubs and "restrict, to a certain extent, the access of commercial insurers" and others who aren't in the clubs to the marine-insurance market.

The probe was prompted by the end of a 20-year antitrust exemption for the protection and indemnity agreements, which were last reviewed in 1999, the International Group of P&I Clubs said in a statement on its website.

The group said it expects regulators will reaffirm their 1999 decision that there were no competition problems because, "there have been no relevant or material changes to the arrangements or in the market for P&I cover" since then.

The commission said there was no deadline for completing its investigation and that companies will have a chance to respond before it makes any decisions. It started the probe on its own initiative and said it hadn't received any complaints.