Richard Wakeling, chief executive of Johnson Matthey, said: 'The acquisition strengthens our position in the semiconductor materials market and offers exciting opportunities for growth, especially in Japan.'
Alta turned over dollars 10m ( pounds 6m) in 1991 and had net assets of dollars 5m. Its titanium technology is likely to be used increasingly in new generations of semiconductors.
The move is seen by analysts as part of a strategy started by Mr Wakeling a year ago to buy up specialist companies with high growth potential.
'We are seeing the manifestation of a very aggressive new management style,' Mike Kurtanjek, analyst with Credit Lyonnais in London, said.
'In a better economic environment Alta should generate two or three times what they have paid for it.'