National Semiconductor will shut its Cyrix PC processor business unless it receives a "solid and acceptable" offer by 30 June. The company blames stiff competition in the PC chip market for its fifth consecutive quarter of losses. it lost around $45 million in the quarter from Cyrix x86 microprocessors. Last month NatSemi announced plans to sell its PC processor business, which it picked up through its acquisition of Cyrix in 1997 for about $550 million. NatSemi recorded a $783.5 million loss, or $4.65 cents per share, for the fourth quarter. This included higher-than-expected charges for exiting the PC chip business. Sales fell to $477 million from $510 million a year ago. Excluding two charges totalling $743.5 million, NatSemi reported an operating loss of $40 million, or 24 cents a share. This compared with a loss before charges of $69.3 million, or 42 cents a share, the previous year, according to Reuters. The loss matched Wall Street expectations. The company expects to be profitable in the quarter ending November after it offloads its Cyrix division, it said. NatSemi CEO Brian Halla said the company could not compete with PC chip giant Intel, and planned to concentrate on chips for products such as TVs and mobile phones. It will also keep Cyrix chips that are used for Web appliances and Windows-based terminals. ®