Sony and Ericsson yesterday officially announced future plans for their much talked-about joint venture.

The venture is to be based in London, with operations also in the US, Japan and Sweden, offering employment to an estimated 3,500 people - 2,500 from Ericsson and 1,000 from Sony.

"We need a deeper understanding of consumer electronics, entertainment, audio, video and design," said Kurt Hellstrom, chief executive of Ericsson at yesterday's unveiling.

Sony will not be involved in the manufacture of handsets but will offer design, branding and marketing input.

Both hope the move will allow Ericsson to pull back its loose grip of the mobile market, which has been failing over the last year, and to allow both companies to achieve a global handset position.

"We are excited about the venture," said a spokesperson at the Swedish mobile comms company, "and are especially happy to be offering new opportunities for our staff."

Sony said it expected to invest around $500m in the project, which will begin operations in October, with products expected by early next year.