Twitter has been privately raising millions in a new financing round, putting the value of the company at $7 billion dollars, according to a report in the Wall Street Journal on Tuesday.

Twitter declined to comment on the report when contacted by CNBC.com. "We don't comment on our finances or speculation about our finances," said a Twitter spokesperson.

Seven months ago, with the help of venture capital firm Kleiner Perkins Caufield & Byers, Twitter raised $200 Million, which valued the company at $3.7 billion.

This year Twitter is expected to make $150 million in ad revenue, according to the Journal.

Although the company is growing, no signs point to Twitter going public, the Journal reported. For now, the company is building up an executive team and working on its advertising plans, which started in 2010.