Oil prices declined Monday as market continued to be plagued by an oversupply of crude oil in global markets.

Iran is ready to increase exports to around 2 million barrels per day in the next six months, said Rokneddin Javadi Monday, the managing director of the National Iranian Oil Co..

The news renewed investors' concerns about the global supply glut, which dragged down oil prices recently.

The Organization of the Petroleum Exporting Countries (OPEC) on Dec. 4 decided to keep crude production pumping at current level in the already oversupplied market.

Meanwhile, due to the shale oil revolution, U.S. oil production has almost doubled in the past six years.

In the week ending Dec 18, U.S. crude production added 3,000 to 9.179 million barrels a day, said U.S. Energy Information Agency in its weekly report.

The West Texas Intermediate for February delivery moved down 1.29 U.S. dollars to settle at 36.81 dollars a barrel on the New York Mercantile Exchange, while Brent crude for February delivery decreased 1.27 dollars to close at 36.62 dollars a barrel on the London ICE Futures Exchange.