Internet search engine giant Google Inc. is doubling down on its investment in Berkeley County, saying today it will spend another $600 million at the company’s local data center site.

Construction will start soon on a third structure that will process search queries and other information. The project take a few years to complete, officials said.

Google did not say how many jobs the expansion will create. It already has about 150 employees at its two existing data center buildings, the second of which is now handling web traffic.

“South Carolina and the Berkeley County community are great places in which to work and grow,” said operations manager Eric Wages. “When Google first announced plans to come to Berkeley County in 2007, we were attracted to not only the energy infrastructure, developable land and available workforce, but also the extraordinary team from the local community that made us feel welcome. Today’s announcement is just a continuation of our investment in the state. Google is proud to call Berkeley County home.”

Mountain View, Calif.-based Google said the investment is part of its strategy “to provide the best possible user experience. The data center in Berkeley County houses computer systems and associated components that support services such as Google search, Gmail, Google+ and YouTube. The company is growing capacity to meet demand for Google’s services.”

Google opened the first data center on the 500-acre site in Mount Holly Commerce Park in 2008 and recently opened the second one next door as part of a combined $600 million investment. Haley called the latest new expansion “another big win for South Carolina.”

“When a world-class company like Google decides to expand in the Palmetto State, it shows we are providing the sort of business environment that helps foster success,” she said.