JPMorgan is in talks to buy a 10% stake in Twitter that could value the popular micro-blogging Web service at $4.5 billion.
News of the potential deal, which was leaked to the press over the weekend, follows last week's reports that the US investment bank has raised $1.22 billion for a new fund to invest in the social media sector.
It is not clear whether the fund will invest directly in Twitter, or buy current investors' stakes, the anonymous sources said.
The $450 million investment wager, mirrors the position taken in Facebook last month by Goldman Sachs, which valued the social networking site at $50 billion. Goldman has since moved to invest $70 million in AppSense, a 12-year old Internet company that lets users access their corporate computers remotely from laptops, tablets and smartphones.
The JPMorgan fund is also reputedly looking for similar investments in other private social media darlings such as Groupon, Zynga and LivingSocial.
Both JPMorgan and Goldman are joining other firms such as Morgan Stanley, T Rowe Price and Tiger Investments by making late stage investments in new media companies in anticipation of another dot com-style IPO boom.