Fairchild Semiconductor

The Schlumberger oil services company said Thursday that it would spin off its money-losing Fairchild Semiconductor subsidiary into a new joint venture with Fujitsu of Japan. Under the agreement, Fujitsu will take 80% of the new company, with Schlumberger retaining 20%. No cash will change hands because of the new venture, although Schlumberger said it would result in a $200-million charge against fourth-quarter earnings.

Schlumberger Ltd., a leading oil services firm that last week ousted its chairman, is likely to sell off its Fairchild Semiconductor division, industry analysts said today. Schlumberger bought Fairchild in 1978 for $425 million, and the manufacturer of microchips has lost money almost every year since. Fairchild, based in Mountain View, Calif., is the nation's second-oldest semiconductor manufacturer behind Texas Instruments. Schlumberger is now run by D.

Schlumberger, the oil-field services giant that bought Fairchild Semiconductor in 1979, announced Thursday a $485-million write-down for the current quarter stemming from its unprofitable Fairchild unit. The charge against earnings probably will give Schlumberger a net loss of about $270 million in its fourth quarter, analysts said. But most of the write-down reflects plant closings already made and accounting adjustments resulting from Fairchild's financial problems.