Micron Slides After Warning That Operating Costs Are Growing (1)

Micron Technology Inc., the largest US maker of computer memory semiconductors, suffered its worst stock decline in two months after warning that it’s spending more than expected on operations.

Adjusted operating expenses will be $990 million in the fiscal first quarter, the Boise, Idaho-based company said on Tuesday. The previous forecast was roughly $900 million. Though Micron increased its revenue outlook to $4.7 billion in the period, up from $4.6 billion, investors had been anticipating a more significant revision.

The stock fell as much as 4.6% in New York, the most since Sept. 28. It had been up 55% ...