Silicon Valley's UberMedia, which was previously known as TweetUp, is thought to be close to agreeing the terms of the deal with UK firm TweetDeck, which offers free software that lets web users track posts on the micro-blogging service.
TweetDeck is currently based in Old Street in London, an area of the UK's capital that the government wants to turn into a British rival to Silicon Valley, and has gained some 20 million users since its launch in 2008 .
Sources close to both company told the Financial Times the deal could be completed within the next month.
UberMedia has also recently acquired UberTwitter and EchoFon, both of which also offer software solutions for updating Twitter.
TweetDeck and UberMedia were unavailable for comment at time of writing.