Former NBC news correspondent Peter Hackes was in Central Casting's office for only a few minutes last January when the owners of the Washington firm whisked him off to the Bristol Hotel for a motion picture audition. A few weeks later, Hackes found himself nervously facing Jack Nicholson and making his acting debut in the hit movie "Broadcast News."

For Carol Ness, who cofounded Central Casting 18 years ago "when there wasn't any need" for a casting company in Washington, placing Hackes in the role of president of the movie's television network news department capped an extraordinary month. Her 10-person firm cast 65 speaking parts and 3,600 extras for "Broadcast News," adding $300,000 in gross revenue to Central Casting's coffers.

That undertaking was followed by "Suspect," which required Central Casting to cast 1,100 extras and 19 speaking parts. The two major movies helped push the company's revenue past $2.5 million last year, compared to $500,000 in 1980.

There's no doubt about it, according to Ness and others involved with filming in the Washington, Virginia and Maryland area: Hollywood has found the Potomac.

Long a scenic backdrop to countless movies, the Washington region now is taking a bigger role in the movie business. With movies like "Broadcast News" being filmed entirely on location in Washington, the region is growing in importance as a movie center, boosting related local businesses and bringing millions of dollars into the regional economy.

In addition to "Broadcast News" and "Suspect," among the movies filmed in or around the region in the past few years were "No Way Out," "Gardens of Stone" and "Dirty Dancing," parts of which were filmed at Mount Lake, a resort hotel near Roanoke. A number of yet-to-be-released films also were made locally, including "Clara's Heart," starring Whoopi Goldberg; John Waters' "Hairspray;" "Li'l Rock and Roller," starring Justine Bateman; "Phoebe," starring Isabella Rosellini, and the NBC miniseries, "Lincoln."

Filming of "The Accidental Tourist," starring William Hurt, is about to begin in Baltimore, and Tri-Star Pictures is planning to film "Life After Life" in Washington this year.

Daily Variety, a trade newspaper based in Hollywood, devoted almost an entire issue last month to the virtues of filming in Virginia. Mike Malek, Daily Variety's director of marketing, said the issue was "a recognition of the fact that filming has become a truly multistate business" and that this region has gotten a generous portion of the business.

Andrew Spaulding, Virginia's film commissioner, estimates that film and television production crews spent $7 million in the state last year. Crystal Palmer, director of the District's film office, estimates an economic impact of $18 million. Both based their figures on spending reported by film companies, and neither used an economic impact multiplier that state film commissions routinely employ in reporting such figures.

Maryland reported a $40 million economic impact, including $5 million from "Clara's Heart," which was shot in Baltimore and the Eastern Shore over two months last fall. But Maryland Film Commissioner Jay Schlossberg-Cohen said he was not certain how the figure was calculated, because many of the numbers were compiled before he took office in August. Maryland hired a new film commission staff in August, including a salesman, to beef up the state's operation.

All three states still are dwarfed by longtime giants California, which reported an economic impact of $6 billion from film production last year, and New York, which reported an economic impact of $2.3 billion. Warm weather states also were running ahead. Florida got $144 million, and North Carolina had $128 million. And the cheaper Canadian dollar has made Canada a haven for filmmakers.

But the Washington region still outpaced many other areas. Noting that Virginia had 10 commercial film and television production projects last year, Malek said, "a lot of states would be happy if they had one or two films in a year." Maryland and the District each had six commercial film and television productions in 1987.

Most of the millions coming to the region were spent on hotel rooms for crews -- which can number as large as 50 to 100 people -- caterers, rental equipment, vehicles, construction materials and local hires. Other beneficiaries include small businesses like EFX Co., a $600,000-a-year computer graphics firm in Arlington, which earned $20,000 doing several special effects for Broadcast News, including a complex three-dimensional animation of an aerial dogfight over the Mediterranean.

One reason for the growth in Washington movie-making, Hollywood executives say, is the public's stronger interest in political stories and more serious movies in recent years. "Suspect" and "Gardens of Stone," for instance, had story lines that revolved around the nation's capital and Arlington National Cemetery.

Steve Saeta, vice president for production management for Tri-Star Pictures Inc., which made the two movies, said filming in Washington requires filmmakers to wade through a maze of government bureaucracies. "There is the D.C. Police, the National Park Service, Congress, Justice Department ... the list goes on and on," Saeta said. In the case of one script, which called for a nighttime scene at the Lincoln Memorial, Tri-Star could not get permission to film there, and the scene was scrapped.

Palmer said she is aware of these problems and said a primary goal of the D.C. film office is to minimize bureaucratic hassles for filmmakers.

Saeta said another problem with Washington is its lack of stages where sets can be built. Tri-Star had to go to Canada to build a courtroom for some scenes in "Suspect."

Nevertheless, Tri-Star is planning to film part of another picture, "Life After Life," in Washington this year. The picture is set in 1988, with flashbacks to 1963. "Washington is one of the few cities that has not changed that much. The majority of the city looks the same because of all the monuments," Saeta said.

Doro Bachrach, the line producer on "Dirty Dancing," said one problem producers encounter in Virginia is the lack of complete film crews, which are available in such places as Atlanta, Pittsburgh, Houston and Dallas. That means crew members must be brought to Virginia from New York or Los Angeles, and that can create problems for independent producers, who often try to hire crews locally to save money. Location costs, which include hotel and expenses for crew members, can amount to $400,000 on a film like "Dirty Dancing," according to Bachrach.

However, Bachrach said, Virginia's position as a right-to-work state makes it attractive to independent producers, who usually have budgets of $6 million or less. In a right-to-work state, the producer -- rather than the unions -- decides the size of the crew and the work schedule.

"All producers are looking for this now," she said. "We saved about $1 million shooting in Virginia and not doing it in New York State because of the union." Movie industry sources say that, to compete, unions in the District and Maryland have been willing to make concessions to get films like "Broadcast News."

Bachrach also praised the Virginia film commission, saying she would go out of her way to work in Virginia because of Spaulding. "Once we decided on the location, Andy Spaulding came right away and granted my every wish, down to the most minute detail," from supplying police for traffic control to finding Jewish-looking extras in southwestern Virginia, said Bachrach.

Bachrach said that shooting part of "Dirty Dancing" in Virginia cost the film an additional $250,000, but that getting the right hotel for key scenes was essential in setting the tone of the movie -- despite the cost and trouble it entailed."Frankly, there's nothing like the right location that determines site," she said. "The {size of} the local crew is important ... and unions. But it's the location that ultimately decides."