US benchmark West Texas Intermediate for July delivery was up four cents at $104.39 a barrel in mid-morning trade and Brent oil for July added nine cents to $109.61.

The Organization of Petroleum Exporting Countries (OPEC), which pumps out about one third of the world's oil, is expected to maintain its production output at a Vienna meeting later Wednesday.

The "OPEC meeting will probably confirm official production target of 30 million barrels per day", research house Capital Economics said.

Producers have said they are comfortable with current price levels at more than $100 a barrel, with Saudi Oil Minister Ali al-Naimi describing the market at "stable and balanced".

Analysts said ongoing disruptions to Libyan output mean there is no pressure on other OPEC members to cut back.

The market is also tracking European Union-brokered talks between Ukraine and Russia to resolve a bitter natural gas dispute while keeping an eye on a weekly US Department of Energy report of oil inventories later in the day.

The US inventories data is important for clues on the state of demand in the world's biggest oil consuming nation.

Analysts expect the report to show a decline of 1.7 million barrels, according to a survey of analysts by Dow Jones Newswires.