The cameras come in for a close-up. The newscaster is not sitting behind a desk, but on the floor. She is not wearing an expensive dress, but a yellow T-shirt and jeans. She has trouble pronouncing a word or two, but the cameramen and producers don't seem to mind.

The newscaster, Melissa Marquez of Olney, Md., is 9 years old. She appears on the Saturday morning program "Newsbag" on Channel 5, a newscast for children and by children.

"Three Americans from Al-buquer-que New Mexico, Ben Abruzzo, Maxie Anderson and Larry Newman, have made history by being the first to cross the Atlantic Ocean by balloon," Melissa says in a whispery voice, lingering over the strange name as she gazes into the cameras.

It was a long sentence for a little girl -- too long, even, for an adult television newscaster. That doesn't worry the producers of "Newsbag." They stand behind the cameras, smiling benignly. "We usually keep in the rough edges," explained executive producer Jill Krasner. "We don't want the newscasters to seem too polished, or kids won't relate to them."

Three other newscasters appear on the show with Melissa -- Avi Adler, 13, of Chevy Chase; Meredith Shore, 12, of Rockville; and Courtney Heath, 13, of Columbia. They were selected from 30 children who auditioned, according to the station, because of their ability to write stories and their relaxed appearance before cameras.

The children spend half the program interviewing people -- dog catchers and fencing teachers -- and the other half relating news and feature stories that they have read in the week's newspapers and magazines. Each newscaster usually selects two news stories and two feature stories. Then, they write their own scripts.

Like most journalists, Melissa has developed certain specialties. She likes reporting on animals, plants, and soap box derbies. She also reports on upcoming events, like puppet shows and county fairs.

"If you're looking for something to do this weekend, let me mention a few things that might be of interest," she tells the cameras. "How about a puppet theater?Hansel and Gretel is showing through Labor Day. . ."

The producers suggest guests for the program, but the newscasters have veto power, usually expressed as "ick."

Recently, Melissa wrote to Amy Carter, asking her if she could interview her on the program. Amy's parents wrote that they were sorry, but Amy couldn't make it. Undaunted, Melissa wrote to Rosalynn Carter's secretary, asking if she could go to the White House to meet Amy. The White House responded to her letter, but evaded her question.

Like other good reporters, Melissa hasn't given up. "Do you know of any way I could meet Amy Carter?" she asked a fellow journalist. "I'd really like to meet her."

Melissa has always wanted to appear on television or in movies. "When I was little I used to think I wanted to be a movie star because movie stars had all kinds of money and everything they wanted," she says. "Now, I know that's not true.

"I used to watch Sesame Street when I was little and that turned me on to television. When I was seven I wanted to be on a clown show but I couldn't. So when I heard about this show I wanted to give it a try."

Melissa thinks she "might want to stay in TV" when she grows up, and perhaps conduct interviews on television, like Barbara Walters.

She is accustomed to performing before audiences. She sang and danced for her parents and company in the past, while her father shone a lamp on her and held up a microphone.

"I want to give my kids as much exposure as I can to life so that when they decide what they want to be, they have a lot of things to pick from," said her father, Rick Marquez, a broadcast engineer for another television station."Melissa takes piano lessons, ballet lessons and swimming lessons. If she finds that TV isn't her thing, she can try something else."