Royal Dutch Shell PLC has issued a profit warning for the fourth quarter, saying results will be worse than most analysts are expecting due to a mix of lower than expected production, higher than expected costs, and a worse than expected performance by its refining division, the Associated Press reports.

The company gave provisional, unaudited figures of net profit of $1.8 billion for the quarter, down from $6.7 billion in the same period a year ago.

Chief executive Ben van Beurden said in a statement the results were "not what I expect from Shell."