OnDeck Capital in New York reported a $5.1 million loss in the fourth quarter as revenue failed to keep pace with rising expenses.

The online small-business lender recorded operating expenses of $47.4 million, up 73% from the same period a year earlier. OnDeck, which went public 14 months ago, attributed the increase to its continued investments in growth.

Revenue also rose, albeit a bit more modestly. Quarterly net revenue was up 67% from the fourth quarter of 2014 to $42.3 million.

The company's fourth-quarter loss followed two profitable quarters. It came during a three-month period that featured the much-ballyhooed announcement of a partnership with JPMorgan Chase, which plans to use OnDeck's technology to make its own online small-business loans.

In a press release announcing the results, OnDeck Chief Executive Noah Breslow emphasized the company's strong loan growth. "In the fourth quarter total originations grew 51% year over year," he said.

OnDeck keeps some loans on its own balance sheet and sells others to investors. In the fourth quarter, as in the third quarter, most of its revenue growth came from the latter business.

OnDeck's gain on the sale of loans was $18.2 million in the fourth quarter, up from just $4.3 million in the same period a year earlier. The company's interest income rose at a much slower rate, from $45.4 million in the fourth quarter of 2014 to $47.5 million.

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