December 3, 1985

As the Union Carbide Corporation passes the first anniversary of the accident at its pesticides plant in Bhopal, India, the company is shaken by giant lawsuits, the threat of a takeover and low employee morale. No American company has had to deal with greater tragedy than Bhopal, where more than 2,000 people were killed a year ago Tuesday in history's worst industrial accident. Now, few companies face a more troubled future. Billions of dollars in Bhopal-related claims remain unresolved. A raft of other suits are pending over the toxic leak last August at the company's plant in Institute, W. Va. Samuel J. Heyman's GAF Corporation has acquired 10 percent of Carbide's stock and is seeking permission from the Securities and Exchange Commission to buy more. And a broad restructuring under way since August - aimed at reducing layers of middle management - has shaken Carbide's work force, according to current and former employees.

The Parti Quebecois, which once advocated at least partial independence from Canada, was overwhelmingly defeated tonight by the Liberal Party after nine years in office. The Quebec Liberal leader, Robert Bourassa, 52 years old, will return to the office of Premier, which he held in two governments from 1970 to 1976. As Liberals waved Canadian and Quebec flags and a band played at a celebration tonight, Mr. Bourassa said, ''What a great victory for Quebec, Canada, and for change.'' But Mr. Bourassa lost to his Parti Quebecois opponent in his own district of Bertrand, near Montreal. As a result, another Liberal may be asked to step aside to create a safe seat that Mr. Bourassa could win in a by-election.

RECENT excavations and interpretive work of scholars have pierced the shrouds that have enveloped the long-lost Etruscan civilization. It has become apparent that knowledge of the Etruscans, who dominated the Mediterranean lands well before the Romans entered history's center stage, has broadened substantially in recent decades, shedding light on such questions as where they came from, who they were and what language they spoke. Modern archeological exploration has veered from the vast burial sites that provided much of the early history of these vanished people to the remains of Etruscan temples, dwellings, storehouses and seaports that were much more difficult to locate than the cemeteries, and therefore less exposed to thievery. The latest research has been reviewed during an international Etruscan congress being held in Italy this year for some 800 scholars from Italy, other European countries and the United States. Findings were presented at a conference in Florence in about 100 papers to be published in a single volume next year.

When Anne Henderson-Pollard was arrested last month, she was planning to offer the Chinese a secret document that describes in detail what American intelligence knows about Peking's spying activities in this country, prosecutors asserted today. In a 23-page document filed in Federal District Court here, prosecutors contended that Mrs. Henderson-Pollard, who has been charged with obtaining classified documents, was more deeply involved in the alleged espionage activities of her husband, Jonathan Jay Pollard, than previously indicated. Neither Has Been Indicted The document is the Government's first assertion that Mrs. Henderson-Pollard had been intending to deliver secret documents to the Chinese. Her husband has been accused of selling secret intelligence documents to Israel. They have not been formally indicted and they have not indicated how they would plead.

In the largest takeover bid in British history, the Argyll Group offered $2.74 billion today for the Distillers Company, the world's leading maker of Scotch whisky, including the Johnnie Walker and Dewar's brands. The bid, which the Distillers board immediately attacked as ''unwelcome and completely inadequate,'' is the latest in a wave of hostile takeover efforts in Britain this year. The big bids have recently led to expressions of concern by corporate executives as well as by senior officials of the Bank of England. Despite the free-market leanings of the Government of Prime Minister Margaret Thatcher, some analysts say that pressure is building on the authorities to take steps to slow the merger activity. ''No company is safe now,'' one investment banker said. ''I think the Government is going to have to do something.''