Medtronic, 3M, Mosaic and St. Jude Medical are among the U.S. companies that boosted their offshore profit holdings last year, according to a new report on the practice.

The combined offshore holdings of the four Minnesota companies grew by nearly 25 percent last year to $31.6 billion. The companies were identified in a recent report by Citizens for Tax Justice as among the 92 Fortune 500 companies whose offshore profit holdings grew last year by $500 million or more. Together, the 92 companies are holding about $1.4 trillion overseas, spelling lost tax revenue since earnings held overseas are not subject to U.S. taxes until the money is brought back into the country, the report said.

The reasons companies keep earnings outside the United States are varied and complex, but lowering tax bills clearly plays a role. The U.S. statutory corporate tax rate is about 39 percent, although the effective tax rate companies pay after breaks and loopholes is significantly lower.

TakeAction Minnesota, a labor-backed group, circulated the Citizens for Tax Justice report Friday to bolster support for efforts underway at the State Capitol to raise revenue by closing certain state tax loopholes.

“These companies benefit from the investments that the rest of us are making and that’s why it’s time for them to pay their fair share,” said Dan McGrath, TakeAction Minnesota’s executive director.

Under the Foreign Royalty Subtraction, a state tax deduction that Gov. Mark Dayton wants to reduce, 80 percent of certain income a corporation derives from its overseas operations or subsidiaries is not taxed by Minnesota.

Shaye Mandle, chief operations office of the Minnesota trade group LifeScience Alley, said the deduction is important. “What it does is make sure R&D stays here,” Mandle said.

According to the Citizens for Tax Justice report, 3M Co. had $8.6 billion in profits outside the United States at the end of 2012, $1.5 billion more than in 2011.

A spokeswoman for the Maplewood-based manufacturer said the holdings reflect the fact the company has operations in more than 70 countries. Last year two-thirds of 3M’s sales were outside the U.S., said spokeswoman Jacqueline Berry.

“We locate our plants and operations close to our operations to meet their needs,” Berry said. “The vast majority of our international earnings are invested in property, plants and equipment in major manufacturing hubs in countries around the world.”

Mosaic had $2.2 billion in profits offshore at the end of last year, up 57 percent from 2011, the report said. The company said in an e-mail: “The majority of our crop nutrients are produced and taxed in the U.S. and Canada, and most of our profits are reinvested in U.S. and Canada production.”

The other Minnesota companies did not immediately respond to a request for comment.

The nonpartisan Congressional Research Service in January released a study on profit shifting that showed that U.S. multinational corporations are shifting profits out of high-tax countries to low-tax countries such as Bermuda.