MONTREAL -- Canadian auto sales hit a record high in May, with General Motors Co (GM.N) and Ford Motor Co (F.N) on Thursday reporting double-digit increases, fuelled by demand for crossovers and light trucks, according to analysts who compile the monthly data.

One economist attributed the record May sales to discounting among the large automakers in a fight for market share.

Automakers sold 216,861 vehicles in May, a number which "smashed all previous monthly records," and was up 11 per cent compared with the same month a year earlier, Canadian auto analyst Dennis DesRosiers wrote in a note.

Year-to-date auto sales in Canada reached 835,582 units representing a 4.7-per-cent increase over the previous year, DesRosiers wrote.

Scotiabank senior economist Carlos Gomes attributed the strong May sales figures to discounting. "I would call it incentive heaven," he said by phone from Toronto.

Gomes said he now expects another record-breaking year for Canadian auto sales. He plans to revise his April forecast that said Canadian auto sales would decline slightly in 2017 to about 1.94 million vehicles, from a record-breaking 1.97 million units in 2016.

By contrast, in the United States, automakers reported sales fell one per cent from a year ago. This brought the annualized sales pace down to 16.66 million cars and light trucks from 17.17 million vehicles a year ago, according to figures compiled by Motor Intelligence.

"We're going to have to increase our Canadian forecast and reduce our U.S. forecast," Gomes said.

In Canada, Ford reported the sale of 34,486 vehicles, up 17 per cent compared with the same month a year earlier and the best sales for a month of May since 1989.

General Motors said it sold 31,149 vehicles in Canada last month, a 36-per-cent rise compared with a year earlier, fueled by demand for crossovers and light trucks.

The company added that was its best performance for May in eight years. It contrasted with a 16.4-per-cent drop in sales in May 2016 versus the year-earlier period.

Fiat Chrysler (FCAU.N) said it sold 33,186 vehicles, up five per cent from May 2016 and the highest monthly Canadian sales in its history.