(Reuters) - MasterCard Inc (>> Mastercard Inc), the world's second-largest credit and debit card network, reported a 21 percent rise in quarterly profit as consumers spent more with their cards and revenue rose faster than expenses.

Executives cautioned, however, that such gains are less likely over the rest of the year because of the strength of the business in the latter parts of 2011, and given doubts about consumer confidence in the United States and in Europe.

MasterCard shares fell 2.6 percent to $445.59 in morning trading on the New York Stock Exchange. Stocks fell broadly after disappointing news on manufacturing in Europe and private-sector job growth in the United States.

CEO Ajay Banga said that while U.S. consumer confidence has been roughly flat for two months, it is still higher than a year ago. Consumer spending in the United States, MasterCard's home market, was up in all 11 categories the company tracks in the first quarter and was strongest at restaurants and at apparel, hardware and electronics stores, Banga said in a conference call.

Cardholders made $629 billion of purchases worldwide during the first quarter, up 17 percent from a year earlier, MasterCard said.

Card payments outside the United States grew 20.6 percent, based on local currencies, compared with 14 percent growth in the United States.

The number of transactions processed increased 29 percent to 7.7 billion, the fastest rate of growth since MasterCard went public in 2006. The increase reflects, in part, the increasing movement of consumers globally to making payments electronically instead of with paper currency.

Net income was $682 million, or $5.36 a share, compared with $562 million, or $4.29 a share, a year earlier, the Purchase, New York-based company reported on Wednesday.

Analysts on average had expected $5.30 a share, according to Thomson Reuters I/B/E/S.

MasterCard net revenue, adjusted for an acquisition, grew faster than expenses, rising 16 percent while operating expenses increased 9 percent.

Visa Inc (>> Visa Inc.), MasterCard's larger rival in card payment processing networks, is scheduled to report its quarterly results following the close of New York Stock Exchange trading.

(Reporting by David Henry in New York; Editing by Lisa Von Ahn and John Wallace)

By David Henry

Stocks treated in this article : Mastercard Inc, Visa Inc.