Survey:MORE evidence chat apps are set to take over from Facebook and Twitter

Chat and messaging apps are increasing replacing social networking sites such as Facebook and Teitter, new figures have claimed.

A study of 5,000 US teens by PiperJaffray found 10% fewer named Facebook as their 'most important' site compared to a year ago.

The teens surveyed were also less interested in Twitter, YouTube, Google+, Flickr, and Tumblr - with only Pinterest showing growth.

The study also looked at which services teens were talking about - and found messaging services such as Kik and Snapchat were popular, alongside Vine, Twitters video-blogging service, messageboard 4chan and shopping site Wanelo.

The report is the latest to claim that Facebook and Twitter face major competition from chat services.

Google has this week played down rumours it is set to buy the WhatsApp service for a reported $1bn, while it is also believed to developing its own chat app called Babel