ECONOMY Productivity of American workers rose at the fastest rate in two years in the third quarter, climbing at an annual rate of 1.6 percent, the government said. However, because productivity plunged at a 1.3 percent rate in the first quarter, it is averaging only a 0.2 percent advance for the first nine months of 1990. COMPANIES Ford might have to delay certain car and truck programs if the Society of Engineering Office Workers, a union representing about 750 salaried workers, goes on strike as it has threatened to do tomorrow. END NOTESUPS ordered 25 Boeing 757 jet freighters from Boeing Commercial Airplane Group. The total value of the order is about $1.7 billion. Continental Airlines pulled the Honolulu-Tokyo leg of its Houston-Tokyo route from a list of assets it may sell, saying that the hard-won route is too important to put on the block. Harcourt Brace Jovanovich's debt rating was lowered by Standard & Poor's. The agency said it was lowering its ratings on $200 million in senior unsecured notes. END NOTES United Press International laid off more employees, a day after company officials said the news service faced liquidation unless remaining workers accepted a 90-day pay cut of 35 percent. The number of layoffs was not announced. Union Carbide's chemicals and plastics company formed an international consortium to build a new ethylene glycol plant in Canada. ACQUISITIONS Wal-Mart Stores agreed to acquire the Wholesale Club for about $170 million to complement Wal-Mart's Sam's Wholesale Club Division and give the discount chain a presence in new markets. Ford Motor Credit agreed to acquire Marine Midland Automotive Financial to form a non-Ford automotive financing business headquartered in Nashville by early 1991. Terms were not disclosed. INTERNATIONAL London's Stock Exchange is investigating more than a dozen suspected "bear raids" in which stock manipulators illegally profit by spreading malicious rumors about companies. COURTS Toyota was ordered by a federal court jury to pay $7.5 million to a Bloomfield Hills, Mich., couple for faulty seat belts in a 4Runner sport-utility vehicle. Toyota said it will appeal. EARNINGS Continental Airlines Holdings reported a third-quarter loss of $88.3 million, compared with a loss of $158 million a year ago. Emerson Electric said its fourth-quarter earnings rose 3.3 percent from the same period a year ago. Columbia Savings and Loan Association, the target of a possible seizure by federal regulators, reported a third-quarter loss of $352 million, compared with a loss of $226.3 million for the same period last year. PEOPLE Laurence and Preston Tisch, along with a group of investors, said they hold a 5 percent stake in Shawmut National.