TOKYO: Sony Corp said it was withdrawing from joint research with IBM and Toshiba Corp to develop the manufacturing technology for producing microchips with circuitry of 32 nanometers or less.

Sony has been moving away from the production of advanced semiconductors, which involves heavy investment.

The Tokyo-based electronics and entertainment company said last month it would sell to Toshiba its production facilities for making the "Cell" microprocessors and "RSX" graphic chips, both of which are used in its PlayStation 3 game gear.

While it is withdrawing from the joint R&D on technology, Sony said it would continue to work with Toshiba and International Business Machines Corp on design work for cutting-edge chips with 32-nanometre or narrower circuitry.

A nanometer is one-billionth of a meter.

Narrower circuitry makes the size of a chip smaller and helps manufacturers cut per-chip production costs. But finer circuitry also means heavier initial investments for microchip makers as costs for chip-making equipment balloon.

Shares in Sony were up 0.5 percent at 5,590 yen by the midday break of trade, outperforming the Tokyo stock market's electrical machinery index, which was down 0.2 percent.