October 28, 1986

DENISE GRIESER was shopping on Lexington Avenue yesterday for a portable radio with an earplug so she could listen to the Mets last night at the opera. Don Blaisdell was buying one as a Christmas present for his son. Amid the Halloween parties and college students' calling parents to say when they would be home for Thanksgiving, baseball has just kept going on. The fans at Shea Stadium dressed in ski wear and consumed hot chocolate in record volumes. The grounds crew used special fertilizers and hoped the grass would not turn brown. The pitchers blew on their hands and started fires in the bullpen.

Unions, real-estate developers and financial houses made up nearly half of the major contributors to Governor Cuomo's campaign treasury, according to an analysis of his financial reports over the last four years. Twenty-five of 134 Cuomo contributors of $10,000 or more were unions, the largest single group. Fifteen real-estate developers and 15 financial houses were also represented as major contributors. All either do business with the state or have a business interest in state legislation.

Amid champagne toasts and computer breakdowns, the London securities markets today stumbled into a new, more competitive era with a burst of deregulation called the ''Big Bang.'' At first it seemed as if the long-awaited bang would be a bust. The London Stock Exchange's new electronic share-trading system broke down this morning, unable to take the strain of a surge of demand for price information from eager dealers and traders. The computer mishap brought trading to a halt for roughly an hour.

The United States told Secretary General Javier Perez de Cuellar today that it would contribute $100 million to the United Nations' 1986 budget, less than half of what it is obligated to pay under the Charter, the chief United Nations spokesman said. The contribution is significantly higher than was forecast after dramatic Congressional cuts. These were expected to slash the American contribution by 70 percent, to less than $60 million. But in recent weeks Administration officials, led by Under Secretary of State John C. Whitehead, began a campaign in Congress to reverse the cuts, arguing that the United Nations was a key forum for American foreign-policy interests.

APART from a few distant high rises and power line towers, this picturesque section of the Seine Valley, 40 miles southeast of Paris, looks much as it did a century ago when painted by Alfred Sisley and Pierre-Auguste Renoir. The scene 12,000 years ago, however, was very different. How different has been revealed from intensive study of riverside hunting camps painstakingly brought to light under layers of sand spread by the river's annual floods. The sands preserved camps here and elsewhere in the Paris basin with minimal disturbance, documenting the ways of life of Ice Age dwellers in detail available in few other places. It is almost as though one could sneak onto an overlook and gaze at the reindeer hunters camped here as the last ice sheet retreated from Belgium to the north. Vast herds of reindeer sought shallow fords across the Seine, and the hunters with their flint-tipped spears awaited them.