Discover Financial Services' net income fell 33 percent in the last three months of 2014, as several one-time charges cut into gains in credit card and loan revenue.
The latest results fell short of Wall Street's expectations, sending shares in the credit card issuer and lender down 3.3 percent in aftermarket trading Wednesday.
One culprit: Lower gas prices. While they are generally great for consumers, they hurt Discover's sales, said CEO David Nelms on a call with financial analysts.
"Our sales growth would have been, with stable gas prices, approximately 1 percent faster year-over-year," Nelms said.
Still, total loans climbed 6.4 percent, as credit-card lending, private student loans and personal loans all increased.
"Our business model continues to deliver solid results," Nelms said.
Offsetting those gains were expenses, which increased 10 percent as Discover spent more on marketing, professional fees and employee pay.
Discover's earnings also were undercut by some $226 million in one-time charges, including $178 million stemming from changes in the company's credit card rewards program and $27 million related to Discover's home loans business.
Meanwhile, transaction dollar volume at Discover's payment services business rose 2 percent to $51 billion.
But litigation over its PULSE payments network will hurt earnings in that division, Discover said.
The Riverwoods, Illinois-based company reported that net income after paying preferred dividends fell to $392 million, or 87 cents per share, for the three months ended Dec. 31. That compares with net income of $588 million, or $1.23 per share, a year earlier.
Excluding the impact of the one-time charges, Discover's earnings amounted to $1.19 per share. Analysts polled by FactSet expected earnings of $1.30 per share.
Revenue, net of interest expense, declined 4 percent, to $2.04 billion from $2.13 billion. Analysts predicted $2.2 billion.
Discover stock shed $1.99 to $58.85 in extended trading. It's down 7 percent in 2015 but has gained 14 percent over the past 12 months.