Airbnb funding round said to value company at more than $10 billion

Airbnb Inc. is raising money from investors including TPG Capital in a financing round that would value the room-sharing service at more than $10 billion, people with knowledge of the deal said.

Airbnb is set to raise about $450 million, said one of the people, who asked not to be identified because the information is private. The closely held San Francisco company — which is backed by venture-capital firms including Sequoia Capital, Greylock Partners and Founders Fund — was last assigned a value of $2.5 billion by its investors in 2012.

At $10 billion, Airbnb would join the ranks of the most highly valued private U.S. technology companies, which includes Dropbox Inc. and Palantir Technologies Inc. It would also be worth more than twice as much as publicly traded vacation-rental site HomeAway Inc.

A slew of technology start-ups has lately raised huge rounds of financing at increasing valuations, as corporate investors, hedge funds and mutual funds seek stakes in fast-growing companies before they go public. The abundance of capital is enabling start-ups to boost their cash to expand operations and staff. Some of the companies are on a path to an initial public offering.

Messaging application TangoMe Inc. on Thursday raised $280 million from investors led by Alibaba Group Holding Ltd., in a deal that values the start-up at more than $1 billion, people familiar with the matter said. Also this week, Cloudera Inc. said it raised $160 million, with more set to come from investors including Intel Corp., people with knowledge of the situation said.

Founded in 2008 by Brian Chesky, Joe Gebbia and Nathan Blecharczyk, Airbnb lets users rent out a couch, bedroom or house and makes money by charging a fee for each transaction. The company has listings in more than 34,000 cities, according to its website.