Compaq Computer last night reported an operating loss for the third quarter due to the economic downturn, the September 11th attacks, a typhoon in Taiwan, and its merger plans with Hewlett-Packard. Compaq, which saw margins fall, expects the fourth quarter to be weak. The firm, which employs up to 2,000 people here, said it lost $120 million (€135 million), or seven US cents a share in the third quarter, compared with earnings of $557 million, or 31 US cents a share in the year-earlier period, and slightly below analysts' consensus forecast.