Alimentation Couche Tard Inc (ATDb.TO) reported better-than-expected quarterly earnings on Wednesday as the world's second biggest convenience store operator benefited from strong motor fuel sales.

Revenue from the Canadian company's fuel retail business, its biggest, jumped 20.5 per cent to US$6.82 billion in the first quarter ended July 23.

Fuel gross margin surged 21 per cent in Couche Tard's Canadian business, but fell slightly in its U.S. retail unit.

Couche Tard, one of Canada's most acquisitive companies, bought 522 convenience stores from Holiday Stationstores Inc in the U.S. Midwest during the quarter. It now has more than 15,000 stores worldwide.

The company, which owns the Circle K chain of convenience stores, closed its US$4.4 billion purchase of U.S. company CST Brands in late June, in its biggest ever deal.

Laval, Quebec-based Couche Tard's first-quarter net income rose to US$364.7 million or 64 cents per share, from US$322.8 million or 56 cents per share, a year earlier.

Excluding one-time items, the company earned 67 cents per share, edging past analysts' average estimate of 65 cents, according to Thomson Reuters I/B/E/S.

Revenue climbed 17 per cent to US$9.85 billion.