(Adds details on the update of site cleanup)
By Scott Haggett
CALGARY, Alberta, Feb 17 (Reuters) - Canadian National Railway Co said on Tuesday it has nearly completed repairs on a stretch of its mainline track in northern Ontario after a crude train derailed on the weekend, spilling oil and causing several of the cars to burn.
The company said in a notice that the site, about 80 kilometers (50 miles) south of Timmins, Ontario, is expected to be cleared by 10 p.m. local time. It did not say if the line, which runs between Montreal and Winnipeg, Manitoba, would immediately re-open once the clean up was complete.
Late on Saturday night, 29 cars carrying Alberta oil sands crude to eastern Ontario derailed from the track and seven caught fire, blocking traffic on the company's main cross-Canada line.
The company, working with regulators, has allowed fires at the site to burn themselves out while the spilled oil has been contained.
"Today crews are working to remove the final few derailed cars from the right of way and proceed with repairs to the track," Patrick Waldron, a spokesman for the company, said in an email. "Due to the bitter cold conditions and isolated location, safety and firefighting experts have allowed the remaining controlled fire at the core of the derailment to burn."
The company said the cars were the CPC 1232 tanker cars, supposed to be a safer model than the older DOT-111 crude tankers that derailed and burned in downtown Lac Megantic, Quebec, in July, 2013, killing 47 people.
A derailment on Monday on a CSX Corp rail line in West Virginia that caused 20 cars to catch on fire also involved CPC 1232 tankers rather than the older version that was criticized as prone to puncture.
The cause of the northern Ontario derailment remains under investigation by Canada's Transportation Safety Board. (Reporting by Scott Haggett; Editing by Bernard Orr)