Jan. 26 (Bloomberg) -- Residual-fuel inventories in Singapore, Asia’s biggest oil-trading and storage center, increased 18 percent in the largest gain in almost a year, according to a unit of the Ministry of Trade and Industry.

Onshore stockpiles including fuel oil and low-sulfur waxy residue and excluding bitumen climbed 2.8 million barrels in the week to yesterday to 18.13 million, International Enterprise Singapore said in an e-mailed statement today. Supplies rose the most in percentage terms since the week ended Feb. 23, 2011.

Middle-distillates inventories including gasoil, or diesel, and kerosene dropped 1 million barrels, or 10 percent, to 8.93 million, based on the ministry’s data. That’s a five-week low.

Stockpiles of light distillates including naphtha, gasoline and reformate were little changed, climbing 9,000 barrels to 11.05 million. Supplies were the highest in six weeks.

The trade ministry surveys refiners, traders and storage terminals on a voluntary basis. The results may exclude offshore storage capacity, International Enterprise said.

--Editors: Paul Gordon, Christian Schmollinger

To contact the reporter on this story: Yee Kai Pin in Singapore at kyee13@bloomberg.net

To contact the editor responsible for this story: Alexander Kwiatkowski at akwiatkowsk2@bloomberg.net