Crude oil output from the Organization of the Petroleum Exporting Countries fell slightly in January as some Libyan output was disrupted and the Saudis kept their supply at lower levels, according to a Dow Jones Newswires survey of industry sources and analysts.

Crude oil production averaged 30.330 million barrels a day in January, just 20,000 barrels a day down from 30.350 million barrels a day in December.

The group's overall output was reined by lower production in
Libya after protesters blocked the Zueitina oil terminal and a strike shut down the Ras Lanuf refinery, both in the Eastern part of the country. Libya 's deputy oil minister Omar Shakmak said production had fallen to an average of 1.34 million barrels a day in January, compared to around 1.4 million barrels a day the previous month. He said the supply had been mostly impacted by the Zueitina closure, though he said it was set to return to normal within 14 working days.

OPEC's production is also capped by lower production compared with most of last year at the group's largest producer,
Saudi Arabia , following a production cut in December.

As a result, "we have moved from oversupply to balance" in the oil market, said Samuel Ciszuk, an consultant at KBC Advanced Technologies.

The current level of production is close to OPEC's ceiling of 30 million barrels a day--the level the group sees as suitable to balance demand and supply.