September 22, 1986

After months of sharp disputes, the United States and the Soviet Union seem suddenly on the road to both a summit meeting and conclusion of a major arms control agreement. Both sides agree, however, that further progress depends on a prompt resolution of the Daniloff affair. Secretary of State George P. Shultz and the Soviet Foreign Minister, Eduard A. Shevardnadze, ended two days of talks Saturday on a note of expectation about a summit meeting later this year. But Administration officials said today that the momentum could quickly be lost if Nicholas S. Daniloff, a correspondent for the magazine U.S. News & World Report, is not freed before Mr. Shevardnadze leaves the United States in the next two weeks. Firm Stand on Daniloff He and Mr. Shultz will be in New York for the General Assembly session that starts Monday and Soviet officials have said Mr. Daniloff's freedom can be arranged there.

International The European Community agreed to buttress the dollar against the West German mark, starting today, according to a Reuters report attributed to an unnamed senior official of the 12-nation group. On Friday, the dollar traded below the 2-mark level for the second day in a row, at its lowest point in five years. [ Page D1. ]

Less than 15 years ago, Michael J. Blumenfeld, a one-time minor league outfielder, broke into the sporting goods business by selling tennis court nets ''door to door'' to Memphis country clubs. Mr. Blumenfeld is still selling nets. But the company that he founded and now runs in Dallas, the BSN Corporation, also sells some 4,000 other athletic items, and its national mail-order operation boasts a clientele list of some 50,000 schools, military bases and other volume buyers. Half of what BSN sells it makes itself - in a network of plants fashioned from a score of recent acquisitions of small sporting goods manufacturers - and its catalogue business is complemented by a controlling interest in a 35-store retail chain. Sales of $42.9 Million The 39-year-old Mr. Blumenfeld is still a long way from becoming the top player in the industry - BSN had sales of $42.9 million last year, compared with $255 million reported by the Wilson Sporting Goods Company, the nation's biggest sporting goods manufacturer. But BSN's aggressive manufacturing and distribution strategy in an industry that has traditionally kept those functions separate has already attracted a large number of fans and detractors.

Apparently undermined by a leaking water main, two large sections of Riverside Drive near 156th Street in northern Manhattan collapsed like sinkholes over the weekend, cutting off water supplies to thousands of residents in the area Saturday night and yesterday. No one was injured, but a crew of city workers digging in search of a leak Saturday night watched in astonishment as a big tree beside them began leaning and sinking, and then, as a crater widened around them, the sidewalk caved in, a mailbox slid down into the hole and a parked car was swallowed up. Eventually, it was an L-shaped maw 60 feet long, 40 feet wide and 8 feet deep that opened at about 10 P.M. Saturday at 156th Street, a block south of a garden that collapsed into an underground garage on the day after Christmas in 1983, forcing the evacuation of hundreds of residents of an apartment building. The second collapse, resulting in a circular hole 40 feet across and 10 feet deep, occurred at about 7 A.M. yesterday near 155th Street, 100 feet south of the first hole. It caused no injuries or damage to other property, though underground gas, electric and telephone lines will have to be moved to make permanent repairs, city officials said.

The 12 nations of the European Community have agreed to a joint effort, starting Monday, to buttress the value of the dollar against the West German mark, the Reuters news service reported today. The report, from Gleneagles, Scotland, where the Community's finance ministers and central bankers met this weekend, was attributed to a senior official who declined to be named. It also quoted Luxembourg's finance minister, Jacques Poos, as saying, ''We want to stop the fall of the dollar by all means possible.'' Mr. Poos added, Reuters said, that ''the general feeling was to stand up and speak with one voice toward the United States.''