IT MAY HELP to know a little about Italian television laws to appreciate Maurizio Nichetti's "The Icicle Thief," an Italian-language comedy with subtitles that opens Friday at the Key.

In his fourth film, Nichetti plays himself as a movie director showing his black-and-white, neorealist film on television; there are breaks for garish commercials, backstage scenes at the studio and glimpses of an easily distracted family watching the show at home. When along the way all the worlds collide, it's good news for everyone but the director.

"Until now, we in Italy have the complete freedom for putting a film on TV without commercials," Nichetti explained last week in a phone interview from New York, where "The Icicle Thief" was opening.

That was thanks to a 1989 court decision in Rome upholding a ruling that commercial interruptions alter a film and thus violate a director's rights. But in the last few weeks, a new law has been enacted enabling private networks to have three interruptions per film. In spite of the artistic calamity such ads cause in "The Icicle Thief," the real-world director and screenwriter sounds fatalistic rather than alarmed.

"My view is a little bit different from all the other autore {directors and artists}," says Nichetti. "I think even when you see a film on TV without any commercials, the TV is not an alternative to the theater. Nobody sees the film with the attention or concentration that a film needs."

The remote control is part of the problem, he says. "When one person is in front of a TV with his remote in his hand, he is the author of his own show. He can choose the beginning and the end of his own show; he can choose when he comes in and out of the film. It is a new kind of show."

There are other differences to consider when watching a movie on TV. "It's another size, another screen, another audience, another color," says Nichetti, who has in fact directed Italian TV commercials and programs in addition to three other movie features. "When a lover of opera or baseball goes to an opera or a stadium, he's not seeing the same show that he sees on TV. I think the same is true for the cinema. The true life of a movie is live in the theater; after it's dead, you see a ghost of it on TV."

Nichetti's not worried that American viewers, who are after all rather used to advertising, may miss some of "The Icicle Thief's" industry jokes, which include an extended homage (verging on parody) to Vittorio De Sica's "The Bicycle Thief."

"I think the most major parts of the film are visual. If you know that 'Bicycle Thief' is a masterpiece of Italian cinema, that's better, but if you don't know that, you still get the gag of the contrast between the black and white film and TV," Nichetti says. "I showed it in Russia, where it won first honors at the Moscow Film Festival; Russians don't understand 'Bicycle Thief' or commercial interruptions, but they laughed nonetheless."

Nichetti's next project involves more multimedia plotting; his enthusiasm for it gives his words an appropriate Italian comedic flair.

"I'm working on another comedy -- always comedy, because I like it so much," he says. Describing the movie as a "love story, but always strange," Nichetti says the protagonist eventually becomes a cartoon.

"It's quite a metamorphosis; at the end of film, he becomes completely a cartoon character, and this is a problem for the girl."