Apple Inc has acquired Quattro Wireless, as the iPhone maker looks to ramp up its presence in the mobile advertising arena.

Quattro announced the deal in a blog posting on its website on Tuesday, but did not give a purchase price. An Apple spokesman also declined to say how much the company paid.

The Wall Street Journal-affiliated blog, All Things Digital, reported late on Monday that Apple would pay $275 million for Quattro.

Broadpoint Amtech analyst Brian Marshall called the deal a good strategic purchase and said it fits Apple's plan to acquire small technology companies that add to ancillary parts of its business.

He also said the deal was a sign of the growing rivalry between Apple and Web search giant Google Inc.

Clearly Apple and Google continue to run down parallel paths ... it's all about mobile advertising on smartphones, they're trying to maximize the dollars they create online.

While Apple's iPhone has been a huge hit, Google's Android platform is also gaining plenty of traction in the smartphone market.

Apple's purchase of Quattro comes on the same day Google is expected to unveil its own smartphone -- the Nexus One -- at an event on its campus.

Quattro is a competitor to AdMob, which Google agreed to acquire in November for $750 million. All Things Digital and other media outlets have reported Apple had also been trying to buy AdMob.

Analysts say Microsoft Corp and Yahoo Inc have also acquired companies with mobile advertising technology in recent years.

Quattro's advertising network spans mobile websites and smartphone applications. The company serves ads in more than 100 countries and its network partners include the National Football League, CBS Interactive and Time Inc.

Quattro counts clients such as Ford Motor Co, Procter & Gamble Co and Visa Inc.

The company was started in 2006. Investors in Waltham, Massachusetts-based Quattro include venture capital firms Highland Capital Partners and Globespan Capital Partners.

Apple declined to comment on its plans for Quattro.

We look forward to developing exciting new opportunities that will benefit Quattro Wireless customers in the future, Apple spokesman Steve Dowling said.

Apple has more than $30 billion in cash and securities, but rarely makes acquisitions. It bought digital music service Lala in December for an undisclosed amount. It acquired chipmaker PA Semi in 2008 for a reported $278 million.

The shares of Cupertino, California-based Apple were up $1.05 cents at $215.06 in midday trading on the Nasdaq.

(Reporting by Gabriel Madway; editing by Dave Zimmerman and Andre Grenon)