BURGER KING WORLDWIDE INC 
While proposals stacked up in Congress, Lew said the Treasury Department was evaluating "what we can do to make these deals less economically appealing, and we plan to make a decision in the very near future."
Senator Chuck Schumer, the No. 3 Senate Democrat, was circulating a draft bill to attack "earnings stripping" often associated with inversions. It was said to be applicable retroactively to deals as far back as 1994.
Policy analysts said Schumer's bill had little or no chance of passage in a Congress deeply divided over fiscal policy and in session for only about two weeks before campaigns intensify. Mid-term congressional elections are set for early November.
Schumer's bill "is profoundly unserious and has zero chance of passing. Instead, it is a piece of political theater," James Lucier, a managing director at research group Capital Alpha Partners LLC, said in a client note.
Although still rare and complex, inversions are becoming more frequent among U.S. multinationals, and have been pursued by companies such as medical technology group Medtronic Inc (>> Medtronic, Inc.) and fast-food chain Burger King Worldwide Inc (>> Burger King Worldwide Inc).
The U.S. government has grappled for more than 30 years with inversions. Fifty-two substantial deals have occurred since 1983, about half of them since the 2008-2009 credit crisis, according to a Reuters analysis.
Laying out his views in a speech at the Urban Institute, a Washington think tank, Lew repeated proposals made by President Barack Obama that would make inversions more difficult. He emphasized the best way to address them was through broad business tax reform.
"Only a change in the law can shut the door, and only tax reform can solve the problems in our tax code that lead to inversions," Lew said.
The likelihood of a thorough overhaul of the tax code this year is very remote, Lew acknowledged, but said inversions represent "one loophole that should be shut down immediately."
"Right now, our tax system rewards U.S. corporations when they buy foreign companies and then declare that they are based overseas ...," he said. "By effectively renouncing their citizenship, but remaining here, these companies are eroding America’s corporate tax base."
Obama has been asking Congress for four years to act on White House proposals to curb inversions, including making them harder to do by lowering the level of continued U.S. ownership permitted for a company to be treated as a foreign corporation.
He has also urged a "substantial business activities" test that would deny foreign company status where operations are still primarily located in the United States and U.S.-managed.
(Editing by W Simon, Chizu Nomiyama and Andre Grenon)
By Kevin Drawbaugh and Emily Stephenson
