AMD says falling chip prices will cause income to be positive but 'substantially lower' than Q3 Tumbling microprocessor prices have prompted Advanced Micro Devices (AMD) to warn of a dip in earnings ahead of its fourth-quarter results at the end of the month.The chip maker expects fourth-quarter operating income to be positive but “substantially lower” than in the third quarter, it said Thursday.The company, which gave no figure, reported operating income of $119 million in the third quarter. AMD attributed the dip in earnings to a sharp drop in prices for PC processors, which largely offset a “significant increase” in unit sales.For the fourth quarter, which ended Dec. 31, AMD expects revenue, excluding its recent acquisition of ATI Technologies Inc., to increase 3 percent from the $1.33 billion reported in the third quarter.Analysts had been expecting AMD to report fourth-quarter revenue of $1.85 billion and earnings per share of $0.23, according to Thomson Financial. AMD, which will report its fourth-quarter results Jan. 23, has been taking semiconductor market share away from rival Intel in the last year with new dual-core processors, forcing Intel into a defensive posture. Technology Industry