November 4, 1985

When Halley's comet vanishes next spring to begin another 76-year loop around the universe, so will demand for Halley's dolls, Halley's comet pills and Halley's glow-in-the-dark clothing. Many of the comet entrepreneurs, however, are vowing not to be left in the comet's celestial wake. Even before the comet has arrived, they are making plans to stay in business after it is gone. Among the variety of ventures that have arisen to promote the reappearance of the famous comet, one company has tapped a special market that it hopes will continue to buy from it when the comet has disappeared. And another foresees turning its new contacts into an international marketing business.

When Edwin J. Gray, the embattled chairman of the Federal Home Loan Bank Board, steps up to the podium of the savings industry's annual convention in Dallas on Tuesday morning he will be talking to friend and foe alike. In almost two and a half years as the top regulator of the nation's savings and loan associations he has irked some by imposing strict regulations on an already beleaguered industry while endearing himself to others for his determination to help the thrift institutions remain independent. The controversy over Mr. Gray's job performance has reached such a point, in fact, that a major topic of conversation at informal gatherings this week at the annual convention of the United States League of Savings Institutions is likely to be whether he will be forced out of his job. Recently, the 59-year-old bank board chairman has been the subject of an intense, but so far unsuccessful, push by Donald T. Regan, the White House chief of staff, to get him out of the post. According to close aides of Mr. Gray, he had planned to resign by the end of the year. Now, they say, in reaction to the reports that he was being forced out, he has shelved those plans and may stay on for several months more.

The crisis in tin trading that started on Oct. 24 is threatening the future of the 108-year-old London Metal Exchange, the world's premier metals market. ''The situation is critical now,'' said David Williamson, director of metals research for Shearson Lehman Brothers Ltd., one of the 28 dealing members on the exchange. ''This could destroy the L.M.E.'' The exchange handles trades in copper, aluminum, lead, nickel, silver, zinc and tin. While most of the actual trading in these metals is done off the exchange, the prices determined by the exchange have traditionally been used to set price standards covering a whole range of commercial transactions between industrial producers and consumers of these metals.

As it entered the fourth quarter, the economy managed to hold the ground it gained in September, the National Association of Purchasing Management said in a report prepared for release today. In its latest survey, the trade association said production levels remained unchanged in October and new orders, the source of future production, eased only slightly. Vendor deliveries continued at virtually the same pace; employment picked up but was still at a low level, and inventories declined as manufacturers began making seasonal adjustments. The purchasing managers' composite index of indicators, a broad measure adjusted for seasonal variation, rose to 51.7 percent, up from 51 percent in September. October was the second consecutive month that the index surpassed the 50 percent mark, having stayed at lower levels for a seven-month run. A reading below 50 percent signals that the economy is contracting; a reading above 50 percent indicates that it is expanding.

International Early elections in the Philippines will be held, President Ferdinand E. Marcos announced. He said that he intended to call for a presidential election in January to settle what he called a ''silly claim'' that his Government is inept. [Page A1, Col.6.] A covert plan aimed at weakening the regime of the Libyan leader, Col. Muammar el-Qaddafi, has been approved by President Reagan, according to Congressional sources and Administration officials. [A1:4.]