WEX Inc.’s second-quarter earnings exceeded analyst expectations despite continued challenges related to low fuel prices and unfavorable foreign currency exchange rates.

The South Portland-based corporate payment services provider said Wednesday that its total revenue for the second quarter increased by 9.5 percent to $233.9 million from $213.7 million in the second quarter of 2015.

During the quarter, fuel prices and foreign currency exchange rates negatively impacted WEX’s revenue by $13.6 million and $2.2 million, respectively, when compared to the prior year period.

The company’s adjusted net income attributable to the second quarter decreased by 12.8 percent to $42.1 million, or $1.08 per diluted share, which was above the high end of the company’s guidance range, from $48.3 million, or $1.25 per diluted share, for the same period of 2015.

According to the investor service Seeking Alpha, WEX revenue beat analyst expectations by $10.2 million, and its net income beat expectations by 6 cents a share.

WEX President and CEO Melissa Smith said the company’s continued growth and diversification has helped reduce the effects of adverse economic conditions.

The company got its start processing fuel payments for companies with vehicle fleets, but it has since branched out into processing patient visits to health care providers and online payments to travel services.

It also has expanded into several countries, including those in Europe and Asia. Most recently, WEX opened an office in Singapore and signed contracts with companies in China, Thailand and Indonesia.

In addition, the company uses a different revenue model in some countries that makes revenue less dependent on fuel prices, Smith said. Initially, all customer payments to WEX were based heavily on the cost of the fuel.

“(Now) it’s not the only thing that’s driving the business, so it gets buffered,” she said. About one-third of WEX’s revenue is no longer tied to fuel prices, she said.

Smith said the company also has made significant progress toward incorporating a former competitor, Nashville-based Electronic Funds Source, into the business.

In October, WEX announced it would acquire the company for about $1.1 billion in cash and 4 million shares of common stock, a deal valued at nearly $1.5 billion and WEX’s largest acquisition to date.

Smith said process of integrating EFS into WEX has been a tremendous undertaking, but that the benefits of the merger are now coming to fruition.

“We’re pretty excited about it,” she said.

WEX is one of southern Maine’s largest employers, with about 700 of its 2,000 total workers at the company’s South Portland headquarters. It has been on a buying spree over the past few years as it expands into payment processing markets for the health care and tourism industries.

Company officials said the EFS deal expanded market share, created efficiencies and provided a more diverse customer base. Still, some analysts have expressed concern that WEX’s reliance on debt for acquisitions could hamper its ability to weather adverse economic conditions.

But Smith said the company’s financial performance speaks for itself.

“It’s been a very dynamic time globally, where we’ve seen more changes than we ever had, and yet the company has continued to grow,” she said.

WEX trades on the New York Stock Exchange under the symbol WEX.