Shutterstock, one of the leading micropayment stock image services, says it has acquired BigStockPhoto, a smaller competitor.

The brands will remain separate and the deal will have little immediate impact on customers and contributors, says Shutterstock CEO Jon Oringer.

Terms of the deal were not disclosed. Mergers are unusual in the crowded microstock space, where about six larger brands and over a dozen smaller ones have been courting online image buyers for several years.

Shutterstock has differentiated itself by offering subscription pricing, which appeals to high-volume customers. BigStockPhoto uses a more common pricing structure of selling credits, which customers redeem for individual image licenses.

Oringer says Shutterstock was looking for a way to reach lower-volume buyers with a credit-based service. “We were in a position where we could either build one or buy one,” he says.

More news from the stock photography world this morning, after leader in the field iStock announced it would be expanding its services to include stock logo sales.

Shutterstock has just announced its acquisition of BigStockPhoto, a credit-based stock photo agency headquartered in Davis, California.

The terms of the acquisition were not disclosed.

Shutterstock, a "microstock" company that sells royalty-free photographs for relatively low prices over the Internet, has acquired rival BigStockPhoto and a new sales method along with it.

Shutterstock had offered its photographs and videos through a subscription payment plan, but BigStockPhoto sells its individually with credits. Both rely on a large pool of photographers to supply them with stock photography used in everything from corporate PowerPoint presentations to tourist brochures.

"This addition will enable Shutterstock to better satisfy the diverse payment preferences of stock photo buyers worldwide," said Jon Oringer, founder and CEO of Shutterstock, in a statement Wednesday.

The sites will be operated separately for now at least, though, so customers and photographers shouldn't notice any immediate difference. Shutterstock plans to expand BigStockPhoto's global presence...

Shutterstock, the world's largest subscription-based stock photo agency, announced that it has acquired BigStockPhoto, a leading credit-based stock photo agency, headquartered in Davis, California. Financial terms of the deal were not disclosed.

"BigStockPhoto is a leader in the stock photo industry, and an excellent fit for Shutterstock as we expand into the credit-based market," said Jon Oringer, founder and CEO of Shutterstock. "This addition will enable Shutterstock to better satisfy the diverse payment preferences of stock photo buyers worldwide."

According to the deal, BigStockPhoto will remain a separate entity, and Shutterstock plans to grow the company's global presence by investing heavily in marketing, infrastructure and user experience.