Chip maker Intel said Monday its fourth-quarter revenue will be lower than expected due to hard disk drive supply shortages.

Intel [INTC 24.045 -0.965 (-3.86%) ] shares tumbled more than 3 percent after the company made the announcement, which came before the opening bell.

Intel said it now expects fourth quarter revenue of $13.4 billion to $14 billion. It had previously forecast revenue of $14.2 billion to $15.2 billion for this all-important holiday quarter.

Analysts polled by FactSet are expecting revenue of $14.65 billion.

Intel is by the world’s largest maker of microprocessors, the “brains” of computers.

The company says it expects PC sales to be up sequentially during the quarter. But it says companies are reducing inventories and microprocessor purchases because of hard drive shortages.