Google Inc's chief executive said the company's fledgling social network, Google+, has scored more than 100 million active users, and he reiterated the Internet search giant's commitment to making long-term bets.

Larry Page, also co-founder who took over the top job from Eric Schmidt in April 2011, said in a 2012 strategy update that the search giant had made progress revamping Google around key business opportunities.

Page said that Google's smartphone operating system, Android, was being activated on 850,000 mobile devices every day.

He signaled Google's intentions to make hardware devices when its $12.5 billion acquisition of Motorola Mobility Holdings closes later this year, even as some observers have speculated that Google was only interested in the company for its extensive patent portfolio.

We are excited about the opportunities to build great devices capitalizing on the tremendous success and growth of Android and Motorola's long history of technological innovation, Page wrote.

Founded by Page and Sergey Brin in 1998, Google has grown into a corporate behemoth, with roughly $38 billion in revenue last year and nearly $45 billion in cash and securities on its balance sheet as of the end of September of 2011.

While Google has dominated Internet searching for a decade, the company has struggled to find its footing in social networking, with Facebook, Twitter and other start-ups stealing Web traffic and engineering talent.

Since Page took back the reins in April 2011, Google has moved aggressively to make the company a force in the fast-growing social networking market, with the launch of its Google+ social networking service.

Our goal is long-term growth in revenue and absolute profit—so we invest aggressively in future innovation while tightly managing our short-term costs, Page wrote.

Page did not provide any new financial details in his letter. Google is due to report its first quarter financial results next week.

Google has also faced criticism about some of its privacy practices during Page's tenure. And it has drawn fire over its search rankings system, with some accusing the search company of favoring its own products over rival services.

(Reporting By Edwin Chan; Editing by Bernard Orr)