OTTAWA, Jan 25 (Reuters) - Canada is worried by U.S. President Joe Biden's plans for a "Buy American" program to boost domestic industry and it will be a priority for talks with the new administration, Finance Minister Chrystia Freeland said on Monday.

The two neighbors have highly integrated economies as well as one of the world's largest bilateral trading relationships and Canada fears its firms could lose out if U.S. procurement rules are tightened.

Biden is expected to sign an executive order later on Monday to increase domestic manufacturing and close loopholes in existing provisions, which structure the $600 billion in goods and services the federal government buys each year.

"I am concerned. We are always concerned by 'Buy American' ... for sure that is going to be an issue very very high on our agenda in our work with the Biden administration," Freeland told reporters.

Canadian governments have had to deal with 'Buy American' provisions from previous U.S. governments only to discover "the devil is very often in the details," she added.

"We find we are very often able to explain to our American partners that trade is in the mutual interests of Canadians and of Americans," she said.

Biden's first conversation with a foreign leader last Friday was with Canadian Prime Minister Justin Trudeau, who raised the "Buy American" issue and urged the President to "avoid unintended consequences that can hurt both countries," a Canadian government source said. (Reporting by David Ljunggren Editing by Chris Reese and Paul Simao)