Photo library and licensing giant Getty Images is to be bought by its founders and investment company The Carlyle Group for $3.3bn. They will buy-out existing private equity firm Hellman & Friedman, which purchased Getty for $2.4bn four years ago. Carlyle, one of the world's largest private equity companies, will gain a controlling share of the company, while co-founders Mark Getty and Jonathan Klein, along with the Getty family, will also increase their stakes in the business.

In a press release about the move, Mark Getty said, 'In 17 years, we have built a business that has revolutionized the industry, with innovation at its core. I am confident that the partnership between Getty Images and The Carlyle Group will see the company’s success continue.'

Getty was the first major agency to license images online and has grown through the acquisition of other libraries and collections. It has also embraced the microstock concept, with its purchase of iStockphoto in 2006 and its deal with photo-sharing site Flickr, that lets users license their images through the company.

However, the glut of microstock images and images taken from the Internet has significantly undermined the traditional image licensing business model and Getty's continued success seems to stem, in-part, from its willingness to license images more cheaply and pay photographers a smaller proportion of the income. Trade group American Photographic Artists complained in 2011 that Getty's latest contracts pushed contributors to allow their images to be sold as part of royalty-free subscription packages, rather than being able to restrict their work so that it was licensed only on the traditional context-specific, per-use (and generally more lucrative) 'rights managed' basis.

The Carlyle Group is one of the world's largest private equity groups, with extensive investments running from the defense industry through to well-known brand names such as Dunkin Donuts.

In an interview with the British Journal of Photoraphy, co-founder and CEO Klein says the deal will allow the company to expand Internationally but that nothing will change, from a contributor point-of-view.