SOUTH PORTLAND — WEX Inc., a credit-card payment processing company, said second-quarter earnings rose 5 percent amid new contracts and favorable fuel prices. 

The South Portland-based company said adjusted earnings totaled $41.1 million, or $1.05 a share, compared with $39.1 million, or $1 per diluted share, for the same period a year ago.

Net income applicable to common shareholders was $42.2 million, or $1.08 per share, compared with $30.3 million, or 78 cents a share, for the second quarter last year. The results topped Wall Street expectations of $1.04 a share.

Total revenue for the second quarter increased 16 percent to $178.3 million from $153.1 million for the second quarter of 2012.

“It was a good, solid quarter,” said WEX Chairman and Chief Executive Michael Dubyak. “The recovery in the U.S. is more equitable throughout the regions of the country, but it’s certaintly not robust.”

Shares of WEX rose 2.35 percent, or $2.02, to $87.89 in afternoon trading.

During the second quarter, WEX won a contract with Citgo and saw solid growth in its core fleet business amid recent acquisitions.

“Executing on our growth strategy, we furthered our domestic fleet business with contributions from Fleet One and some key private label client wins. In addition, our investments in WEX Virtual are spearheading our expansion into the travel vertical, as we broadened our international presence within Europe, Asia-Pac and South America,” Dubyak said.

During the second quarter, the average number of vehicles serviced worldwide rose 10 percent to about 7.4 million. Total fuel transactions processed increased 12 percent from a year ago to 93.4 million. U.S. retail fuel price decreased 2.4 percent to $3.70 per gallon from $3.79 per gallon in the second quarter of 2012. 

For the third quarter of 2013, WEX expects revenue in the range of $186 million to $193 million and adjusted net income to be in the range of $45 million to $48 million, or $1.16 to $1.23 per diluted share.

Wall Street analysts expect WEX to earn $1.17 a share on revenues of $187.97 million in the third quarter.

For the full year 2013, the company expects revenue in the range of $718 million to $728 million and adjusted net income to be in the range of $167 million to $171 million, or $4.27 to $4.37 per diluted share.

Analysts expect WEX to earn $4.29 a share on revenues od $713.13 million for the full year.

The company, which employs about 1,400 worldwide, said it continues to explore options for the expansion or move of its corporate headquarters within Maine.

WEX has grown through a series of acquisitions, including last year’s $369 million deal to buy fuel-card company Fleet One from private-equity firms. Other recent deals include buying 51 percent of UNIK SA, a Brazilian provider of payroll cards, for about $21.9 million, as well as acquiring CorporatePay, a London-based provider of corporate prepaid cards for the travel industry, for about $27.5 million in cash.

Dubyak said WEX has the financial reserves to make additional acqusitions, but it also plans to grow more on its own and it remains optimistic about its fleet business and travel operations.