Oil prices have fallen to under $49 per barrel on Thursday following an increase in US inventories.

Brent eased 21 cents to $48.94 a barrel, while the US crude slipped 51 cents to $46.15, Reuters reported.

American Petroleum Institute (API) data revealed a rise in crude stocks in the US by 9.4 million barrels in the week to 9 October to 465.96 million, which is in contrast to analyst forecasts for an increase of 2.8 million barrels.

Investors are keenly watching for inventory data to be released by the US Government’s Energy Information Administration (EIA) today.

"In December, the fed will hike rates and OPEC will not cut output.."

Some analysts anticipated a further decline in the coming months with a possible rise in interest rate in the US making the dollar value stronger. This makes oil more expensive for other currency holders.

SEB Oslo chief commodity analyst Bjarne Schieldrop told the Reuters Global Oil forum: "So here is the set up: in December, the fed will hike rates and OPEC will not cut output. In Q1 of 2016, global oil inventories rise further and oil prices will drop."

The Organization of the Petroleum Exporting Countries (OPEC) is set to meet in December and is expected to hold to its policy of maintaining market share.

During the first nine months of 2015, the big oil exporters worldwide have increased crude production by more than half a billion barrels, Reuters data revealed.