Russian venture firm Digital Sky Technologies (DST) has reportedly invested $400m in US social media company Twitter as part of an $800m funding round.
The Russian firm will receive a 5% stake for its investment, according to news provider Financial Times. Twitter confirmed on its blog the latest funding round was led by DST.
T Rowe Price, an US mutual fund and a fund run by US-based bank JP Morgan had also invested in the company, the FT said.
The FT added it was unlikely Twitter would go public before 2013.
Half the money was expected to be used to provide an exit for current investors and Twitter employees, news provider All Things Digital said last month.
If the investments complete, Twitter would have raised $760m since it was founded five years ago, All Things Digital said.
DST is backed by Chinese internet firm Tencent.
Twitter, in its blog statement confirming a DST-led investment, said: "Just a year ago, we delivered 65 million Tweets a day. Today, we generate over 200 million Tweets per day. One year ago, there were approximately 150,000 registered Twitter apps. Now, there are more than one million that connect to Twitter. And our team has grown from 250 people to more than 600 in the past 12 months."