ZURICH (Reuters) - Swiss bank UBS UBSG.S may ask U.S. regulators to expand its license to sell more complex products and sophisticated investment advice to wealthy Americans living in Switzerland as it seeks to woo U.S. taxpayers abroad for growth. In an interview published on Sunday, Chief Executive Sergio Ermotti told Swiss newspaper SonntagsZeitung that UBS currently cannot sell some products and investments to U.S. taxpayers in Switzerland.

CEO of UBS Sergio Ermotti gestures during a press preview of U.S. photographer Annie Leibovitz's exhibition 'WOMEN: New Portraits' at Wapping Hydraulic Power Station in London, Britain January 13, 2016. REUTERS/Stefan Wermuth

Ermotti did not specify which products, but a banking source told Reuters they would be investments and advice that UBS’s Swiss-based Swiss Financial Advisers unit (SFA), which caters to U.S. taxpayers the country above a certain wealth threshold, cannot offer now.

According to the source, UBS is reviewing options and is likely to approach the U.S. Securities and Exchange Commission (SEC) to seek regulatory permission for some currently off-limits products.

The source did not name specific products under review.

Expanding UBS’s license could help it compete against U.S. rivals just as the largest Swiss bank is seeking more business with wealthy U.S. citizens living abroad, to help accelerate its wealth management business where transaction volumes have been modest.

“Most billionaires are Americans,” Ermotti said in the newspaper interview. “We don’t want to just cede that business to the U.S. banks.”

In 2009, UBS paid $780 million to settle a dispute over wealthy Americans who had stashed undeclared money in Swiss accounts.

The source said the limits on what products UBS could offer affluent U.S. taxpayers in Switzerland were not a consequence of that dispute. Rather, its current license with the SEC simply does not cover them.

Ermotti told the newspaper that U.S. banks had worked “cleverly” with politicians in that country to take advantage of the tax dispute to advance their commercial interests.

Still, the Swiss banker said UBS, which maintained a strong U.S. presence even after its settlement, is strong enough to overcome any disadvantage.

“We have something special to offer,” he told SonntagsZeitung. “As David against Goliath, we can do well.”

(This version of the story corrects paragraph 3 to show products and advice in question cannot currently be offered by UBS, clarifies in paragraph 5 that license would help UBS compete against U.S. rivals)