Apple has signed a deal with the state governor of North Carolina, which will see the iPod maker spend $1 billion (£623 million) in building a major data centre in that state.

The bill with North Carolina will give Apple an estimated $46 million in tax breaks over the next 10 years. But the company could save more than $300 million in state income taxes if the data centre is in place for 30 years.

Although Apple confirmed that it has chosen North Carolina as the location for the data centre, it has not yet disclosed the actual site. The company did not reply to questions about the location of the centre and its intended purpose.

The data centre will employ at least 50 full-time employees once it's built out to its full capacity over the next nine years, and create an additional estimated 250 local jobs for outside contractors for such things as security, landscaping and maintenance, Governor Bev Perdue said yesterday.

"We welcome Apple to North Carolina and look forward to working with the company as it begins providing a significant economic boost to local communities and the state," Perdue said in a statement.

The state's commerce department estimated that the data centre would create 3,000 regional jobs when everything, including the construction of the centre, is factored in.

Earlier in the week, the state's legislature had passed a specially-crafted tax incentive bill that changed the way state corporate income taxes are calculated for a capital-intensive operation. Although Apple was not named in the bill, it was widely rumoured in the last few weeks to be the target of the measure, which was written in such a way that Apple was one of the few companies eligible for the tax breaks.

According to the bill, Apple must meet wage standards for the centre's jobs, provide employees with health insurance and build the facility in an economically-distressed county. The last requirement has fuelled speculation that Catawba and Cleveland counties are the leading candidates to land the project, according to reports on several North Carolina newspapers' websites.

Catawba County, which is northwest of Charlotte, the state's largest city, has the edge over Cleveland County, directly west of Charlotte, said the Charlotte Observer.

Opponents of the bill have blasted the preferential treatment during a time when the state faces a $4.5 billion budget shortfall. An earlier incentives package made to Google, which built a data centre in Caldwell County in 2007, has been challenged in court. The $600 million Google data centre is located in Lenoir, North Carolina, which is just 32 miles from the Catawba County locale predicted for Apple's facility, and 61 miles from a potential location in Cleveland County.

"Technology-driven projects like this may bring fewer overall jobs than traditional industry, but they have a tremendous economic impact through locally purchased goods and services," Keith Crisco, the state's commerce secretary, said in a statement.

Apple has not said what the centre will be used for, but a similar server farm just south of San Francisco hosts iTunes content and the MobileMe online sync and storage service.