Google Inc. announced Friday it would invest another $600 million in its Berkeley County data center, doubling the Internet giant's investment in South Carolina.

"I'm a proud governor today but I'm also a proud Googler," Gov. Nikki Haley told about 100 local elected officials and business people at a groundbreaking ceremony on a windy field at the company's campus south of Moncks Corner.

The company launched the campus with a $600 million investment six years ago.

"Let me be clear to people across South Carolina: Google has now invested $1.2 billion in the best state in the country," the governor said, adding "$600 million is one thing. And additional $600 million is an absolute celebration."

The company, for proprietary reasons, did not say exactly what the expansion would do or how many additional people would be employed. But Eric Wages, Google's data center operations manager, said that construction would begin shortly.

Haley joined Wages and local officials in using brightly colored shovels to symbolically turn the first dirt for the expansion.

With its initial $600 million investment, the company built two data center buildings on the campus. The second came on line recently and currently about 150 people are employed at the South Carolina site.

The data centers include large banks of computer servers that process everything from Internet searches to email, inquiries to Google maps, YouTube videos and other services.

Wages said Google would be advertising for candidates for the new jobs, and hiring workers with backgrounds in everything from engineering and data networks to security and facilities management.

Haley said that having companies ranging from BMW to Boeing and Michelin to Google are a selling point for South Carolina and help to attract other major companies, and the jobs they bring, to South Carolina.

"It's a great place to do business. It's a great place to live and we are selling South Carolina like we never sold it before," she said.

She credited Goggle with also being a company that gives back to the state.

In the past six years, Google has donated more than $900,000 to local schools and help put in a free Wi-Fi network in nearby Goose Creek.