Some 10 per cent of Japan's workforce in assembly and processing operations will have been replaced by robots by 2015, analysts predict.

Labour shortages in Japan will be among the key growth drivers, according to Tokyo-based Nomura Securities.

The analyst firm expects that the number of robots used in industry will rise more than 76 per cent by 2015.

Industrial robots are found in many roles, but are most commonly used for welding, particularly on cars and other vehicles in the auto industry. Specialised robots are also used to transport partly finished components inside computer chip factories.

Nomura believes that around 920,000 industrial robots were in use worldwide in 2005.

Of these 40 per cent were in Japan, 32 per cent in Europe, 15 per cent in North America and 12 per cent in Asia, excluding Japan. Nomura predicts this robot population to rise to 1.62 million by 2015.

Japan has an ageing population, high salaries and a relatively slow rate of immigration, making robots a particularly attractive addition to the workforce for industry.

The country also hosts several leading manufacturers of robots, an industry already worth more than $3bn in annual sales and exports for the nation, according to the Japan Robot Association.

"We think that the underlying market for robots used in the new applications of assembly and processing is worth over $600m a year in Japan alone," wrote Nomura analyst M Hirokane in a report published last week.

"We make this calculation on the assumption that 10 per cent of the 1.43 million people that worked in assembly and processing operations in 2005 will be replaced by robots, and that replacement investment will last 10 years."

Some local manufacturers, such as Yaskawa Electric, are working on robots that can safely work alongside humans on factory production lines. The robots are designed to act as assistants for their human colleagues.

"Instead of just being used in the auto industry, we think that robots will be used in applications such as tightening screws in mass-produced items such as TVs, audiovisual equipment, PCs and printers," said Hirokane.