U.S. companies won some concessions from the Internal Revenue Service (IRS) following proposed regulations that would soften the blow of a new foreign tax—but the rules didn't go as far as the business community had hoped.

The agency issued guidance Wednesday that would in some ways allow businesses to minimize the hit when calculating how much they owe for the new levy on their GILTI, or global intangible low-tax income. Companies have to allocate only half—instead of all—of certain domestic expenses to foreign subsidiaries, which effectively lowers their GILTI liabilities, according to the regulations.

The IRS also gave companies some leeway to take advantage of their unused foreign tax credits after they voiced concerns that the law wouldn't do enough to account for the taxes paid to foreign governments.