SINGAPORE (REUTERS) - Singapore's Maritime and Port Authority (MPA) revoked the sales and operation licenses of Seaquest Tanker and Vermont UM Bunkering because of erroneous record keeping on their tankers, according to an MPA press release on Thursday.

The MPA took away the bunker craft operator license for Seaquest Tanker Pte Ltd and the operator and bunker supplier licenses for Vermont UM Bunkering Ltd, the statement said. The MPA conducted checks on Seaquest Tanker in 2015 and Vermont UM Bunkering in 2016 that led to the removals.

The MPA took away the licenses after finding discrepancies and wrongful declarations in the records kept on board their bunker vessels, the statement said. "There were also separate incidences of transfers of bunkers between bunker tankers that were conducted without MPA's approval," the statement said.

Vermont's revocation was effective April 27 while Seaquest's revocation was effective April 26.

Telephone calls to the listed numbers for Seaquest and Vermont UM were not answered.

Singapore is the world's biggest bunkering, or ship fuelling, port.