High-tech is best market - for now

''No entry-level positions available'' read signs posted on many company booths set up at the technical-career job fair in a hotel here last week. What is available is barely understandable to a technology newcomer: for instance, listings for a sr. RF manufacturing engineer; external resources engineer, and pagination systems-software engineers.

But this job fair isn't meant for babes in the technology woods. The companies on the lookout for experienced talent are industry heavyweights: IBM, Wang, Raytheon, McDonnell Douglas, Sperry, RCA, Kodak, Texas Instruments. And many of the candidates eyeing them are qualified professionals - already holding down a job, but getting ready to move on to greener pastures.

At a fair like this, which lasts two days, 2,500 to 3,000 candidates will browse for career information or jobs. ''And there is the potential for a company to do 8, 10, 15 hires,'' comments Michael Hall, marketing vice-president for Business People Inc., the Minneapolis company that runs the fair.

In the last five years, BPI has built a strong business around technical job fairs. Last year it rang up $2 million in revenues on 24 fairs held in 15 cities. This year, it's hoping for $3 million. Arnold ''Bill'' Aberman, BPI president, emphasizes the firm is not an employment agency.

Job fairs for all sorts of industries have traditionally been run by the company seeking to hire or a number of companies with similar needs banding together. But, lured by the need to match experienced technical people with jobs in a fast-growing industry, a number of outside firms have entered the business in the last few years.

''At this point, it (high tech) is the most active place in the marketplace, '' comments Sanford Rose, of Sanford Rose Associates. For the past year and a half, this Akron-based employment agency has been running high-tech ''opportunity centers'' where companies meet individually and confidentially with candidates. Last year, the centers grossed over $1 million.

For a company to get a slot at a BPI fair, it must pay between $2,000 and $2, 500 for a booth. For candidates, there is no fee or registration - incentives for employees who want to shop for other jobs, but don't want their boss to know about it, BPI executives say.

''If we get one hire, it will be very cost-effective,'' says Mary Anne O'Connor, a recruiter from Comsat TeleSystems, a satellite-communications company. ''An ad in the Boston paper will cost $3,000; the Wall Street Journal, relations.'' Mrs. O'Connor points out that even if Telesystems doesn't hire anyone - which is unlikely - people that come to chat may talk the company up among their engineering friends.

Paul Billiveau, technical personnel advisor for Raytheon Data Systems, has been attending the BPI fairs for a couple of years now. ''This is where the greater concentration of talent is,'' he says.

At the moment, BPI is considered the leader in the job-fair business. ''It has a lot of market recognition,'' says Beth Pape, an account executive with Thompson Recruitment Advertising and former writer of a technical-recruiting newsletter. ''They draw the largest crowds, because of the way they do business.''

Heavy promotion in the Sunday papers the day before the fairs open is part of the reason BPI's Mike Hall says the company does so well. But he emphasizes that BPI has a commitment to do ''more than just rent hotel space.'' He says the company is becoming an expert in the kinds of candidates ''out there'' - who they are, where they are, and when they're likely to be available. BPI is taking on the added role of ''consultant'' with its clients, Hall says.

BPI's closest competitor is an employment firm, Lendman Companies, based in Virginia Beach, Va. In addition to running closed interview fairs similar to the ones handled by Sanford Rose Associates, this $5 million company this year introduced its own high-tech ''open'' fairs.

But Stephen Campbell, president of Lendman, thinks there should be more to a job fair than the chance to do a little matchmaking. That is why the Lendman job fairs include guest speakers on pertinent technological subjects.

These ''make (the fair) an attraction to people who might not be actively in the market for a job, but are interested in getting acquainted with state of the art,'' he said. And, despite BPI's claim that no registration means ''privacy'' in the job search, Campbell says having other reasons - like a lecture - to attend a job fair gives a person a good excuse if he should run into his boss.

The open fairs Lendman runs now get most of the company's spending and publicity attention. With recovery on the way, Campbell says, not only will high-tech firms step up their use of the fairs, so will heavy industry. Smokestack companies, traditional Lendman clients, ''simply have to turn their production facilities toward high-tech.''

The challenge for the technical job-fair business will not be competitors like BPI, Campbell sums up, but expanding the market: ''From this point forward, what all of us have to look forward to is getting more companies to discover how useful (a fair) is. It's an easy sale to make once a company comes and tries us.''