By Julie Gordon

VANCOUVER, Feb 14 (Reuters) - A Canadian government-backed review of the type of rail car involved in last year's deadly Lac-Megantic crash found that industry, regulators and shippers could do more to ensure the safety of the cars that carry crude across North America.

The report, made public by Transport Canada late on Friday, also said that older model DOT-111 cars should be retrofitted or retired over the longer-term, and recommended a feasibility study on how those retrofits could be performed.

A series of accidents, including the derailment and explosion that killed 47 people in Lac-Megantic, Quebec, in July, has forced regulators and the industry to re-examine the safety of tank cars that transport oil.

The crude-by-rail business has grown rapidly in recent years, buoyed by increased production in Western Canada and North Dakota without an accompanying boost in pipeline capacity.

In the wake of the Lac-Megantic disaster, Canada's transport minister in November commissioned three working groups including industry and unions to study the classification of dangerous goods, emergency response, and the DOT-111 cars, and make recommendations.

The oil that exploded in the Lac-Megantic derailment was carried in DOT-111 tanker cars that pre-dated new, tougher safety standards introduced in October 2011.

While DOT-111 cars built since 2011 comply with new requirements, some 228,000 of the older cars remain in service in North America, with 92,000 of them being used in flammable liquid service, the report found.

The report on Friday urged Transport Canada to consider recent calls by the Association of American Railroads for "an even higher standard of design safety of the DOT 111 new build tank cars."

Last month, Canadian and U.S. safety agencies urged regulators to act quickly to impose tougher safety standards for the crude-by-rail sector, including phasing out the old DOT-111 cars "sooner rather than later."

But experts say it could take months, if not years, to put new rules in place and it is unclear how long it will take to phase out the older cars.

Canadian Pacific Railway Ltd and Canadian National Railway Co both said this week that they will charge extra for customers that transport crude in the older-model tank cars.

Earlier this year, Canadian Transport Minister Lisa Raitt promised Canadian and U.S. officials would act "fairly soon" on new safety standards for oil tanker cars.