IT's business as usual at National Semiconductor's factory at Greenock after the company was bought by Texas Instruments in a deal worth $6.5bn (£4bn).

“All National’s plants, including its Scottish factory at Greenock, will continue to operate as usual,” said a spokesman for the company.

National Semiconductor also has factories in the US and Malaysia.

Bringing the two companies together under one umbrella will make Dallas-based Texas Instruments the third-largest semi-conductor manufacturer in the world.

Analysts at consultants IHS iSuppli said the companies earned combined revenues of $14.5bn (£8.9bn), which beat Toshiba’s $13bn (£8bn) but are dwarfed by Samsung’s $27.8bn (£17bn).

National Semiconductor is rated 37th in iSuppli’s revenue rankings.

“This acquisition is about strength and growth,” said Rich Templeton, the chairman and chief executive of Texas Instruments.

“National has an excellent development team, and its products combined with our own can offer customers an analogue portfolio of unmatched depth and breadth.”

Don Macleod, National Semiconductor’s chief executive, added: “Our two companies complement each other very well, Texas Instruments has much greater scale in the marketplace, with its larger portfolio of products and its large global sales force.

“This provides a platform to enhance National’s strong and highly profitable analogue capability, power management in particular, leading to meaningful growth.”

Computer industry analysts said Texas Instruments would gain a much wider business footprint. IHS iSuppli said the deal would increase the chip firm’s current leadership in analogue integrated circuits to about 9% higher than second ranking STMicroelectronics.

Texas Instruments is also likely to benefit from National’s voltage regulator business, as that part of the acquisition will give it a quarter share of the entire market.

ISuppli explained that, while semiconductor sales grew 93% in the past year, the voltage market grew 169.4%, rising to $9.1bn (£5.6bn) in 2010 and tripling since 2001.

The deal will also boost the manufacturing facilities available to Texas Instruments, allowing it to extend to plants in Maine, Scotland and Malaysia.

National employs 440 people at its manufacturing facility in Greenock. The plant has been a centre for analogue design, development and manufacturing since 1970. The facility is also home to a design centre comprising custom solutions design and power management design.

National’s Scottish factory makes analogue products including regulators, audio amplifiers, comparators, power management integrated circuits, LED drivers, gate drivers, automotive products and display drivers.

Although the deal is agreed, it still requires the nod from National’s shareholders.