Google Inc said on Tuesday it acquired marketing start-up Wildfire to help the world's largest Internet search company expand further into social media.

Google paid about $250 million for the business, according to a person familiar with the deal. The source is not authorized to speak publicly about the transaction and requested anonymity.

Wildfire provides software that links to Facebook Inc, Twitter, LinkedIn Corp, Pinterest and other social networks, allowing customers to manage their online brand and presence. Wildfire's clients include Sony Corp and Amazon.com Inc.

The deal is the latest in a string of social media acquisitions by Internet and enterprise software companies.

Salesforce.com Inc snapped up Buddy Media in June for almost $700 million, and Oracle Corp has acquired several social media businesses this year, including Involver, Vitrue and Collective Intellect.

Google bought social media start-up Meebo for about $100 million in June.

"There's still a lot of opportunity for advertisers to get their message out on social media," said Ben Schachter, an analyst at Macquarie. "As more and more social sites are being used, such as Pinterest, it gets more and more complicated for companies and brands to manage."

Wildfire business should fit well within Google because the company specializes in technology that helps advertisers reach consumers online, the analyst added.

Founded by Victoria Ransom and Alain Chuard in 2008, Wildfire has about 400 employees and powers social media marketing for more then 16,000 businesses, including 30 of the top 50 global brands.

Google plans to slot Wildfire into a group of online ad services offered through its DoubleClick business.