The return to work of CN Rail employees helped Canadian imports and exports set record highs in March, Statistics Canada said today.

The expansion of imports outstripped that of exports, causing the country’s trade surplus to contract to $4.6 billion from $5.2 billion in February.

During that month, conductors and yard-service workers at CN Rail went on strike for 15 days, disrupting parts of the country’s transportation system.

Canadian companies exported $40.6 billion worth of merchandise in March, up 1.4% from February. Automotive products led the growth of exports, rising a “robust” 7.9% to $7.4 billion, StatsCan said.

Imports surged 3.3% in March, reaching a record high of $35.9 billion. Energy products led the gain.

Meanwhile, the United States reported that its trade deficit in March widened more than expected to US$63.9 billion as the country imported more foreign oil. That’s the highest deficit figure in six months.

Even though U.S. exports to Canada hit a record high that month, the U.S. trade deficit with Canada rose to US$5.7 billion.