MONTREAL -- Apparel manufacturer Gildan Activewear Inc. says its net earnings fell nearly 19 per cent in the first quarter compared to its record performance a year ago.

The maker of socks, underwear and T-Shirts says it earned US$67.9 million in the period ended April 1, compared with US$83.5 million in the prior same quarter the previous year.

That equalled 31 cents per diluted share, down five cents from a year ago.

Excluding one-time restructuring and acquisition costs, Gildan earned US$74.6 million or 34 cents per share in adjusted profits. That's down from US$90.1 million or 39 cents per share in the first quarter of 2017.

Sales were US$647.3 million, down 2.7 per cent from US$665.4 million. That's despite a 3.2 per cent increase in activewear sales due to price increases.

Hosiery and underwear sales, meanwhile, were down 20 per cent as Walmart, Target and other large retailers are shifting to more house brand apparel with low prices.

Gildan says the results were in largely in line with its expectations and reaffirmed its guidance for 2018.

The Montreal-based company says international sales grew 24 per cent in the quarter.

It also launched its full assortment of Gildan-branded men's underwear on Amazon.

The company says results were impacted by higher raw material and other costs, along with investments in e-commerce and distribution.