Hayward-based Ultra Clean Holdings warned that its revenue for the fourth quarter of 2012 would fall below previous estimates issued by the semiconductor equipment maker.
Ultra Clean estimated that revenue would range from $88.5 million to $90 million.
That's short of the earlier estimate, issued Oct. 22, of revenue ranging from $94 million to $99 million.
Ultra Clean, which makes products for the semiconductor equipment, flat panel, medical, energy and research industries, will release its fourth-quarter and full-year operating results Feb. 19.
The company's shares plunged 5.5 percent Tuesday and closed at $4.80.