Imperial Oil Ltd. said its Nanticoke refinery, which was hit by a fire on Feb. 15, has started processing crude oil again but won't be back to full production until mid-March.

The company said it is still trying to get additional fuel supplies into the Ontario market from other parts of Canada and the United States, but Imperial said the supply situation in Ontario remains very tight.

The problem was exacerbated by the recent strike by CN Rail conductors and yard-service workers. Rail cars are used to bring fuel into Ontario when extra supplies are needed.

The refinery fire has meant fuel outages at Esso stations, and at Canadian Tire gas bars that get their supplies from Imperial. Other companies, including Shell and Petro-Canada, have also experienced shortages as they struggle to cope with increased demand.

"Our employees are working around the clock to make the necessary repairs to the damaged unit, find additional supplies for the Ontario market and manage critical needs," Simon Smith, Imperial's vice-president and general manager of fuels marketing, said in a release.

In the wake of the refinery fire, the average cost of a litre of regular gas in 10 major markets rose to 98.1 cents, MJ Ervin & Associates, a firm that analyzes gas prices, said Tuesday.

The new average represents an increase of 5.8 cents over the last week and is the highest average reported since the $1.03 recorded in the Aug. 22, 2006, MJ Ervin survey.