President Barack Obama could substantially curb financial secrecy in the U.S. by requiring federal contractors to disclose their owners, a basic step that financial transparency advocates say would help reverse America’s burgeoning reputation as one of the world’s biggest tax havens.

The U.S. ranks third on Tax Justice Network’s financial secrecy index, making it more secretive than traditional tax havens such as the Cayman Islands and Panama.

Only Kenya ranks ahead of Delaware as the easiest place in the world to set up a shell company, according to a 2012 study. The International Monetary Fund last year said there had been “no real progress” in the U.S. at enhancing corporate transparency since 2006. Other U.S. states, such as Wyoming and Nevada, also allow individuals to easily create shell companies that cloak identities and enable them to dodge the Internal Revenue Service or their home country tax collectors.

“Financial secrecy provided by the U.S. has caused untold harm to the ordinary citizens of foreign countries, whose elites have used the United States as a bolt-hole for looted wealth,” the Tax Justice Network said.

Financial secrecy is receiving renewed attention with this week's publication of news stories based on millions of leaked documents from Panamanian law firm Mossack Fonseca that suggest world leaders and oligarchs have concealed their wealth using secret shell companies and offshore accounts.

The Obama administration has claimed it is a global leader in advocating for transparency in the financial system, a necessary ingredient if nations want to combat tax evasion and illicit activities such as terrorism, money laundering and drug trafficking.

But as the U.S. government has pushed some foreign governments to enable the IRS to identify American tax cheats stashing money abroad, the Obama administration has done little to combat financial secrecy in the U.S, transparency advocates say. The White House also has shown scant effort to help foreign governments identify their tax evaders who may be using secret shell companies in the U.S. to hide assets.

“It appears as though the administration is pursuing policies that actually won’t solve the problem, but will make it look like they're trying to solve the problem,” said Clark Gascoigne, who heads the Financial Accountability and Corporate Transparency Coalition.

Anonymous companies are the “getaway vehicle” for corruption, according to The B Team, a group of business leaders advocating for financial transparency that includes Paul Polman, the chief executive of Unilever; Marc Benioff, the chief executive of Salesforce; and Arianna Huffington, Huffington Post Media Group editor-in-chief.

In a report last year, the group said corruption increases the cost of doing business by up to 10 percent, and is equivalent to a 20-percent tax on foreign businesses.

Gabriel Zucman, an economics professor at the University of California, Berkeley, estimates that about $7.6 trillion, or 8 percent of the world’s net financial wealth, is hidden in tax havens.

Proponents of financial secrecy say there are legitimate reasons why some individuals and companies would want to shield their dealings from public view, including concerns about privacy and fear of kidnappings or other crimes that could be committed against the ultra-wealthy.

A potential executive order from Obama requiring non-publicly traded federal contractors to identify their true owners is among actions the administration could take to limit secrecy in financial transactions and reduce opportunities for corruption.

Transparency advocates say the Obama administration also could aggressively support pending bipartisan legislation in Congress that would require state authorities to obtain the identities of individuals who own shell companies and share that information with law enforcement; strengthen pending administration proposals to force banks to identify the true owners of bank accounts; and end the exemption from anti-money laundering rules enjoyed by the real estate industry.

With just nine months left in office, there’s little chance Obama and a Republican-controlled Congress will work together to enact anti-secrecy legislation, three years after the White House said it would advocate for such legislation only to let it languish.

A 2014 Treasury Department proposal requiring banks to identify the true owners of bank accounts is riddled with loopholes, transparency advocates said. The International Monetary Fund last year criticized the proposal as inadequate. The Treasury Department said the proposal will soon be reviewed by the White House, usually the final step before federal rules are finalized.

And it’s unlikely the Obama administration will revoke the real estate industry’s exemption from anti-money laundering rules, particularly because the White House won’t have time to finalize rules before the end of Obama’s term. The Treasury Department could make permanent a limited and temporary program that tracks secret all-cash buyers of high-end real estate in Manhattan and Miami.

The ideal solution -- comprehensive public registries that record the beneficial owners of U.S. real estate and financial instruments -- is unlikely to gain traction among senior policymakers, even though Zucman said the registries would be a “powerful way to promote financial transparency, fight money laundering, the financing of terrorism and tax evasion.”

A potential White House directive targeting federal contractors is perhaps the easiest way that Obama could combat financial secrecy in the U.S. A White House spokesman declined to comment on the idea.

A 2011 investigation by Reuters found that anonymous companies registered in Wyoming had won federal contracts worth more than $1.6 million. Though a tiny sum compared with more than $400 billion the U.S. government annually spends on goods and services, transparency advocates told the White House in November that the purchasing power of the U.S. government could have far-reaching influence on business conduct here and abroad.

“If they don’t, they’re undermining their own initiatives,” Eryn Schornick, a policy adviser at anti-corruption group Global Witness, said of a potential White House refusal to require federal contractors disclose their true owners.

Meanwhile, several European countries are moving to create central registries that track the true owners of companies, a step the U.S. has yet to take.

“The U.S. once was a leader on this stuff, but now we’re lagging,” Gascoigne said. “It’s a big problem.”