Singapore ex-wharf 500 CST bunker fuel sales rose 23% year on year to 7.7 million mt in 2013, Maritime and Port Authority of Singapore data showed.

The year-on-year surge eclipsed the 11.6% growth seen in 2012 and the 5.5% increase in 2011, the data showed.

The total was the highest on the MPA's online database for 500 CST bunker sales, which dates back to 2006.

Separate data from global fuel testing agency Det Norske Veritas Petroleum Services released this week also reflected the increasing use of 500 CST, based on shipowner requests in Singapore to test 500 CST bunker fuel purchases. In 2013, about 9-14% of all test requests were for 500 CST, up from 5-9% in 2012.

In 2013, about 9-14% of all test requests were for 500 CST, up from 5-9% in 2012.

In the UAE port of Fujairah, DNVPS saw tests for 500 CST comprise 4% of all tests in 2013, while there were no 500 CST test requests at all in 2012.

In the European port region of Amsterdam-Rotterdam-Antwerp, tests for 500 CST comprised 6-9% of all tests performed in both 2012 and 2013. The company does not disclose the number of tests it conducts.

Major shipping lines are increasingly switching to 500 CST from 380 CST as it is cheaper, a trade source said Monday, adding that most 500 CST was purchased via term contracts rather than spot deals. The 500 CST grade is typically cheaper than 380 CST because of its higher viscosity.

The price of 500 CST in Singapore averaged $603.91/mt in 2013 compared with $615.19/mt for 380 CST, Platts data showed.