How does Twitter's valuation stack up?

Twitter is currently in talks with investors to raise a new round of financing, The Wall Street Journal is reporting.

Citing anonymous sources, the Journal reported today that Twitter's financing could be based on a valuation of $7 billion. If that's the case, Twitter's valuation has skyrocketed over the last couple years.

In 2009, reports surfaced that claimed Twitter was raising funding on a valuation of $1 billion. Last December, Twitter secured $200 million in funding in a round led by venture-capital firm Kleiner Perkins Caulfield & Byers. That round was based on a valuation of $3.7 billion.

In February, The Wall Street Journal and The New York Times reported that Twitter was in talks with J.P. Morgan Chase to offer the bank a minority stake in the social network on a valuation of $4.5 billion.

Though Twitter's value has continued to grow, the company is still one of the smaller start-ups on the Web in terms of valuation.

The king of the start-up mountain is Facebook. Over the past few years, the world's largest social network has seen its value soar. In the last several months alone, Facebook's valuation has grown from $50 billion in January when it reportedly raised $500 million in a round of financing led by Goldman Sachs and Digital Sky Technologies to a reported $70 billion last month when the company sold off 225,000 shares to investment firm GSV Capital.

Also last month, CNBC reported that Facebook was planning an IPO in the first quarter of 2012 that could see the company offer shares based on a valuation of $100 billion.

Business-networking site LinkedIn, which went public in May, is also more valuable than Twitter. As of this writing, the company's market capitalization stands at $8.57 billion.

Twitter's reported valuation is also dwarfed by daily-deals provider Groupon. That company, which filed for its IPO last month, is planning to raise $750 million when its shares go public. Reports suggest that the company could be valued at between $20 billion and $25 billion, based on the information Groupon has filed with the SEC.

Even LivingSocial has a higher valuation than Twitter. The daily-deals company, which filed for its IPO late last month, will have a valuation of between $10 billion and $15 billion when its shares are offered.

However, Twitter's valuation does trump those of some Web companies. Streaming-music provider Pandora, for example, currently has a market capitalization of $3.04 billion. Social network Foursquare raised $50 million last month based on a reported valuation of $600 million.

Twitter did not immediately respond to CNET's request for comment on its current valuation and whether it's planning to raise more cash.