SAN FRANCISCO, USA: Google Inc has acquired Aardvark, a San Francisco start-up whose service melds Internet search and social networking.

Aardvark co-founder and top strategy manager Max Ventilla told Reuters his company had signed a deal to be acquired by Google "recently," but would not comment on the price.

A report on the technology blog TechCrunch said the deal was for $50 million, citing a source briefed on the transaction.

A source familiar with the situation told Reuters the deal was expected to close within the next week.

The purchase represents the latest sign of Google's interest in the fast-growing social networking market, ruled by companies like Facebook and Twitter. On Tuesday, Google introduced a new product called Google Buzz that integrates Twitter-like social networking features directly into its Gmail Web-based email service.

Aardvark, which counts two ex-Google employees among its founders, has pioneered a new type of Internet search dubbed "social search." Instead of looking at Web pages to find answers to search queries, Aardvark's service taps a person's network of social contacts.

The deal is Google's sixth purchase announcement since September, as it picks up the pace of acquisitions.

The Internet giant said in a statement that it had signed a definitive agreement to acquire Aardvark, but it did not yet have any additional details to share