SOUTH PORTLAND — Second-quarter income for Wright Express Corp. shot up 33 percent and revenue increased 55 percent, the company said.

Earnings per share, after excluding income from fuel derivatives, were 91 cents a share for the three months ending June 30, the company said. Analysts surveyed by Thomson Reuters had anticipated earnings of 87 cents a share.

Wright Express, which is headquartered in South Portland, said it saw solid growth in the number of  vehicles serviced, average transaction amounts and purchases using a corporate credit card issued by Wright Express.

The company provides business payment processing and information management, particularly for corporate and government vehicle fleets.

Total income for the quarter was $35.5 million, up from $26.8 million a year ago. Those figures do not follow generally accepted accounting principles, but the company believes they represent a more accurate picture of its financial performance.

For instance, the second-quarter non-GAAP figures exclude a $13.9 million gain from fuel-price derivative instruments. That gain was non-cash, non-realized and valued on a mark-to-market basis.

“The second quarter was another great quarter for Wright Express. We once again reported robust growth in our other payments solutions segment, and benefited from strong fleet transaction and vehicle growth, as well as higher fuel prices in our fleet segment, relative to the prior year,” said Michael Dubyak, chairman, president and chief executive officer of Wright Express.

Dubyak also said the company is successfully integrating and expanding its operations in Australia, where it purchased a subsidiary last September.

The company increased its income guidance for the rest of the year, saying it now expects third- quarter adjusted net income of 89 to 95 cents a share and full year income of $3.50 to $3.62 per share.