December 30, 1984

Change is taking place these days in the midblock buildings west of the property on Fifth Avenue where W. & J. Sloane's once had its store. The midblock buildings once used by Sloane's - a 12-story structure at 5-9 West 37th Street and two structures of 8 and 12 stories sharing a common facade and a single address, 8 West 38th Street - are being transformed into office space.

As the most important Soviet visitor in 15 years left for home today, officials on both sides asserted that an important watershed had been passed in the long struggle to re-establish good relations between the two Communist powers. Attention among Soviet and Chinese officials here focused less on the economic and technical agreements reached during the nine-day visit of First Deputy Prime Minister Ivan V. Arkhipov than on the warm atmosphere that prevailed throughout his stay. One Soviet official recalled the situation after President Nixon visited here in 1972, a trip that he said was important more for the fact that it occurred, and for its friendly atmosphere, than for any notable political breakthroughs. 'Atmosphere Has Been Changed' ''Now,'' the official said, ''our side has come, and although we haven't overcome the big problems, the atmosphere has been changed.''

HOUSTON OFFICIALS of the Transco Energy Company still shudder at the memory of that bitter 1976- 77 winter when, facing a harrowing shortage of natural gas supplies, they had to cut off service to as much as 45 percent of their pipeline's market. Despite desperate attempts to make good on delivery commitments, scarcely any industrial customers of the company's Transcontinental Gas Pipe Line Corporation subsidiary were unaffected, and some had to shut down plants. Fears were rife that the shortage would spread to higher priority customers all along the East Coast - schools, homes, even hospitals. ''We were a prime example,'' recalled Brian E. O'Neill, the pipeline's president, ''of a pipeline that developed a substantial shortage problem.'' Eight years later, the situation is reversed. Transco and the rest of the industry face a prolonged glut - more technically described as ''excess deliverability'' - brought on by deregulation, recession and price-induced conservation of gas and oil. Competition and price have become dominant considerations, a change that has been beneficial to consumers, but that is causing upheaval throughout the gas industry, particularly for pipeline companies.

Through most of its first eight basketball games this season, St. John's carried the weight of national recognition like a man with bogus credentials, treading softly for fear of being exposed. Suspicions from without combined with nagging doubts from within to create an unspoken feeling among the Redmen that before the Big East Conference season began, they needed proof that they were one of the country's elite teams. The unequivocal proof came yesterday at Madison Square Garden as the Redmen defeated North Carolina State, 66-56, to win the Eastern College Athletic Conference Holiday Festival tournament for the seventh time in its 33-year history. It was the eighth victory in 10 games for St. John's and the second loss in nine games for the Wolfpack.

IN sports, 1984 produced some of those memorable moments that will always be seen in the instant-replay of our minds - Mary Lou Retton's vault, Doug Flutie's pass, Kirk Gibson's home run, Billy Johnson's downhill, Martina Navratilova's loss, Dwight Gooden's fastball, Fuzzy Zoeller's putt, Mary Decker's fall. For anyone aware of those moments, the performer will never be separated from what happened. In that flash of memory, the athlete will be automatically accompanied by what he or she accomplished, or failed to accomplish. It's been that way for many others in many other years - Bobby Thomson, Joe Namath, the Olympic hockey team, to name a few. When moments such as those occur, the personality is forever attached to it, if not shaped or haunted by it.