TORONTO - Auto parts company Martinrea International Inc. (TSX:MRE) reported an increase in its first-quarter earnings and revenue compared with a year ago, helped by an improvement in North American auto production.

The company said Tuesday it earned $23.1 million or 28 cents per share for the three months ended March 31 compared with a profit of $14 million or 17 cents per share a year ago.

Sales totalled $735.7 million, up from $431.2 million.

Excluding one-time items, Martinrea earned $24.7 million or 30 cents per share for the quarter up from $19.9 million or 24 cents per share a year ago.

The average analyst estimate had been for a profit of 32 cents per share, according to analysts polled by Thomson Reuters.

Martinrea attributed the year-over-year increase to the inclusion of Martinea Honsel in its results as well as an increase in customer production volumes in North America and productivity and efficiency improvements.

Martinrea acquired Honsel AG, a German supplier of aluminum components for the automotive and industrial sectors, last year in a deal valued at $179 million.

The improvements were offset by costs during the quarter predominantly at the company's Shelbyville, Ky., factory and pre-operating costs at the company's new plant in Silao, Mexico.

Martinrea produces metal parts, assemblies and modules and fluid systems for the automotive sector.

Shares in the company, which reported its results after the close of markets, were up eight cents at $9.35 on the Toronto Stock Exchange on Tuesday.