Nothing about the narrow cream-colored lobby at 160 Aldersgate Street in the City of London financial district gives a hint of its role at the center of the offshore oil industry.
That's because the building is occupied by a law firm. Yet, on paper at least, it is also home to Rowan Companies, one of the largest operators of drilling rigs in the world.
In 2012, Rowan, which has a market value of $4 billion, shifted its legal and tax base from the United States to Britain. But not much else.
"We changed our corporate structure and we're legally domiciled in the UK but our headquarters and our management team remain in the U.S.," Suzanne Spera, Rowan's Investor Relations Director said in a telephone interview from Houston.