Twitter said to have bought TweetDeck for $50 million

Co-founder of Twitter Jack Dorsey attends the 6th Annual Focus For Change: Benefit Dinner And Concert at Roseland Ballroom on December 2, 2010 in New York City.

Twitter has acquired the popular social media aggregator TweetDeck for between $40 million and $50 million, in a move linked to the return of co-founder Jack Dorsey to its management lineup.

The transaction will be announced in the next few days, TechCrunch reports.

The $40 million to $50 million purchase price for the U.K. outfit includes both cash and Twitter stock, says a TechCrunch source. The cash and stock deal could close in less than 10 days, and would represent one of five-year-old Twitter's largest acquisitions to date, Reuters reports.

TweetDeck, one of the most widely used Twitter applications available, had been previously courted by Bill Gross’s UberMedia, with a figure of $25 to $30 million being discussed.

But Twitter — which allows people to send 140-character text messages, or Tweets, to groups of so-called followers and is one of the Web's most popular social networking services, along with Facebook and Zynga — quickly provided an unsolicited counter offer, TechCrunch reports.

This deal is being described as defensive, with Twitter unwilling to allow UberMedia so much market share.

UberMedia owns UberTwitter, EchoFon and a number of other Twitter-related startups, and adding TweetDeck to the UberMedia stable of products would give them too much leverage over Twitter, TechCrunch reports.

The deal comes a month after Twitter co-founder Dorsey returned to the company as executive chairman to oversee product development, Reuters reports.

Twitter has risen in popularuty and, some say, utility, having played a role in several geopolitical events, such as recent uprisings in the Middle East. It is increasingly used by celebrities to build and communicate with fan bases, and by politicians and businesses for promotion.