The company also raised the high-end of its estimated range for full-year earnings per share, despite uncertainty over questions from United States government anti-trust investigators on how it is adjusting to new federal limits on fees charged merchants for debit card transactions.

Quarterly profit, excluding an accounting benefit from a revaluation of deferred tax liabilities, rose 23 percent from a year earlier to $1.08 billion, or $1.60 a share, the company said.

Analysts, on average, had estimated that Visa would earn $1.51 a share, according to Thomson Reuters I/B/E/S.

The company also disclosed in a filing with the Securities and Exchange Commission that it received a "civil investigative demand" on March 13 from the Antitrust Division of the U.S. Department of Justice for documents and information about its response to a new law and rules limiting debit card fees.

CEO Joseph Saunders said later in a conference call with analysts that, while he does not know the goal of the investigators, "obviously they must have a concern" that Visa is taking actions that would undermine the new rules.

"We are confident our actions are appropriate," Saunders said.

The company has met with the department twice and provided materials to investigators, he added.

Visa will inevitably lose some of its dominant market share of the so-called "swipe fee" revenue as a result of the new regulations, Saunders said. The new rules grew out of a law that was enacted following lobbying by retailers, many of whom have long been at odds with major credit and debit card companies over the fees they charge for handling transactions.

The company has received requests for information from the department on four other occasions since 2007 and those inquiries took nine to 24 months to complete.

With the new case, he said, "we have, obviously, very seriously considered various things that may or may not happen, and we have taken it into consideration in crafting our guidance" for full-year financial results.

The company forecast that earnings per share for the full fiscal year would increase by a percentage in the "high teens to low twenties." It said three months earlier that it expected the growth would be in the high teens.

The financial report on Wednesday covered the three months ended March 31, which was the second quarter of the company's fiscal year.

Without the adjustment for the tax liability, net income for the quarter was $1.29 billion, or $1.91 a share, compared with $811 million, or $1.23 a share, a year earlier, the company said on Wednesday after the close of New York Stock Exchange trading.

Earlier in the day, MasterCard Inc (MA.N), which operates the second-biggest card processing network, reported a 21 percent increase in quarterly net income and stronger operating margins on additional card spending.

(Reporting by David Henry in New York; Editing by Steve Orlofsky and Andre Grenon)

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