The U.S. Chamber of Commerce challenged an Internal RevenueService rule change it claims improperly stymies the ability ofU.S. companies to shift their headquarters overseas to shelterglobal profits from American tax collectors.

The Washington-based chamber and a Texas trade group sued thegovernment Thursday, objecting to a policy the IRS implemented inApril that they say wasn't made available for public comment first.The change makes it significantly less profitable for companies tomerge with foreign partners to be considered foreign-based entitiesfor U.S. tax purposes, a practice known as inversion.

“Although it might seem esoteric, this action is a clear case offederal executive branch officers and agencies bypassing Congressand short-circuiting legislative debate over a hotly contestedissue by unilaterally imposing the administration's preferredpolicy,” the groups said in the complaint in federal court inAustin.