The U.S. trade deficit widened in May as exports declined by the most in three months, an indication that businesses were making fewer sales to overseas customers, Bloomberg reported.

The gap grew 2.9 percent to $41.9 billion from the prior month’s revised $40.7 billion, according to Commerce Department figures released today. The median forecast in a Bloomberg survey of economists called for a $42.7 billion shortfall. Exports dropped 0.8 percent on declining demand for commercial aircraft and industrial equipment.

Domestic crude production further reduced America’s imported fuel bill, which dropped in May to the lowest level since February 2002. While persistent U.S. household spending led to record automobile imports, unsettled European and Chinese economies are limiting prospects for a pickup in exports.

“We have weaker growth abroad, and we’re looking at the lagged effects of a stronger dollar restraining exports as well,” Jay Bryson, global economist at Wells Fargo Securities LLC in Charlotte, N.C., said before the report. “With domestic demand in the United States remaining pretty solid, that pulls in imports at a faster rate than exports.”

The U.S. ran a trade surplus with its largest trade partner, Canada, in May for the first time since 1990, MarketWatch reported. The U.S. surplus with Canada was $644 million in May, compared with a year-ago trade deficit of $2.7 billion, the result of a stronger dollar and less demand for foreign petroleum amid an explosion in domestic oil production.

The so-called petroleum gap for the U.S. has been falling for several years as fracking unlocks vast deposits of previously unreachable fossil fuels, reducing the nation’s need for foreign oil.