MONTREAL -- Dollarama's cash registers rang up a strong first quarter with double-digit increases in both sales and profit.

The Montreal-based retailer's net income rose by 28.4 per cent to $83.2 million from $64.8 million.

Revenue was up 13.2 per cent to $641 million from $566.1 million, in part because its retail network grew to 1,038 stores from 972 a year earlier.

Comparable store sales was up 6.6 per cent from last year's first quarter, fuelled by an increased number of transactions and a larger average transaction price.

Dollarama Inc. (TSX:DOL) says the profit was equal to 63 cents per share of net income, up from 50 cents a year earlier -- helped by a share buyback program that has reduced the amount of stock outstanding.

The company says its profit has been helped by the higher revenue as well as improved margins, which rose to 37 per cent of revenue from 36 per cent a year earlier.

The company says it has received approval to renew the buyback program for another year.