The Maritime and Port Authority of Singapore (MPA) has banned bunker supplier Palmstone Petroleum from operating in Singapore, after the homegrown company allowed an unlicensed firm to illegally provide bunkering services.

The MPA said in a statement on Monday that Palmstone Petroleum had flouted rules under its bunkering licence by allowing another company to use its Bunker Delivery Notes to supply bunkers to customers of another firm. This is the third such case this year.

MPA said that the bunker supplier's licence is not transferable and all licensed bunker craft operators are also advised not to make use of any bunker tankers to deliver bunkers on behalf of any person, firm or company that is not a bunker supplier licensed by MPA.

In 2012, Singapore recorded bunker sales volume of 42.7 million tonnes, retaining its position as the world's top bunkering port.