Electric car manufacturer Tesla has become California's leading employer in the automotive industry.

The firm has overtaken Toyota, which plans to move some of its operations to Texas, and now employs 6,000 people in the state, Blue and Green Tomorrow reports.

One of the region's largest local employers, Tesla's workforce is larger than that of Twitter and Facebook.

Earlier this year, the firm's chief executive Elon Musk announced the building of a 'gigafactory' - a giant battery cell factory that could employ a further 6,500 workers. The plans came as a result of the strong sales and revenue growth Tesla has enjoyed in the last year.

A Tesla spokesman announced a further 500 employees would be joining the workforce by the end of 2014.

Gino DiCaro, spokesman for the California Manufactures & Technology Association, said: "Tesla's scaling up here in California is terrific news. It's also an exception - and we certainly need more of them."