December 16, 1985

Economists, mortgage bankers and other housing industry analysts yesterday sharply criticized the Reagan Administration's plan to sell the Federal Housing Administration to private bidders by the end of 1989. ''If you're going to sell the F.H.A., you're effectively selling the American homebuyer down the river,'' said Warren Lasko, executive vice president of the Mortgage Bankers Association of America. Created by the National Housing Act of 1934 to combat the effects of the Depression, the F.H.A. has provided mortgage insurance to more than 51 million homeowners, enabling many to receive mortgages they otherwise would not have been able to obtain. The agency made a profit of $9.4 million last year.

A Spanish-language television station signs off for the night with a ''buenos noches.'' Then the studio technicians, all young people of Hispanic origin, discuss the next day's schedule. In English. A Harvard-educated bank executive, newly arrived from Boston, spends his first weeks studying the Spanish language and Hispanic history. The bank president, also a non-Hispanic, goes to a dance studio after work to learn salsa. A Georgia-born secretary rattles off a list of employees attending an insurance company picnic. ''Dominguez . . . Guerrier . . . Gutierrez . . . Santiesteban . . .'' she calls out without a hitch, accenting each syllable correctly, before stumbling upon a Polish surname.

IN completing a lost weekend, the Giants were unable to do what the Jets were unable to do - win a big game that would have simplified their status in the Super Bowl XX playoffs. And when somebody mentioned to Phil Simms after the 28-21 loss to the Dallas Cowboys yesterday that ''people say the Giants don't win the big game,'' the blond quarterback's face flushed in anger. ''People say, people say,'' he blurted, punctuating his words with obscenities. ''I'm proud of myself and the team. I'm tired of hearing the Giants can't win the big game.''

Every so often, Victor Harris, the president of Max Factor's Japanese subsidiary, is pressed by his American supervisors to attack the weaknesses of the Japanese cosmetics giant, Shiseido. But he says: ''I've spent a career examining their weaknesses, and you're not going to find any major ones.'' Mr. Harris, whose company is a leading foreign cosmetics concern in Japan, gives Shiseido top grades in marketing, production, quality and management, all of which have helped to push the company to the top here. Last year, Shiseido had sales of $1.5 billion.

''Is this some sort of tradition?'' asked Malcolm Blair, an Englishman, peering down into the skating rink at Rockefeller Center yesterday. ''I'm from Brooklyn,'' replied Lila Wood, ''I have no idea what this could be.'' Thousands of shoppers and sightseers jamming midtown yesterday crowded around the rink to behold the Yuletide spectacle of 300 tuba-bearing revelers walking gingerly on the ice beneath Prometheus and the Christmas tree to play a Christmas concert. The tuba enthusiasts have performed this ''TubaChristmas'' every year since 1974, and although it may not be in the class of the ''Messiah'' or ''The Nutcracker'' yet, in America, 12 years straight is a tradition.