Like tremors, the isolated financial difficulties at some technology companies are being felt throughout the dot-com economy as firms and the people running them adjust not only their business plans, but their very expectations for a tech community that once viewed itself as invincible.

Take the case of T-Direct Inc., a Fairfax firm that hoped to start booking flights, hotels and rental cars for business travelers soon. It was just a day away from programming its online travel site for business customers when it had to stop. PSINet Inc., which reported a $1.38 billion loss in the third quarter, was building T-Direct's Web site applications, and both parties got the jitters.

Lauren Howell, T-Direct's vice president of sales and industry relations, said her company needed more money than it had anticipated for PSINet's services. Meanwhile, PSINet, under siege on Wall Street, began having second thoughts about whether T-Direct was the kind of company it wanted to take on as a new customer. PSINet officials declined to comment for this story.

"There was a little insecurity on both sides," Howell said. "For PSINet, we were a debt because we weren't live. So the decision they had to make was how much they want to carry, and it wouldn't make any sense for them to have more debt than was necessary.

"It's so disappointing, because we were really rolling along," Howell said. "Sometimes things just happen that are beyond anyone's control."

The dot-com world is being hit hardest chiefly because of high-tech companies' interconnectedness. So many did business with one another or were dependent on one another for services that a collapse at one of them is felt by all, the way ripples fan out from a rock dropped in a pond.

Gene Riechers, managing director of the venture capital firm FBR Technology Venture Partners in Reston, said the area high-tech community "has benefited from a ripple effect of growth--buying from and selling to each other--and that ripple effect can go the other way."

Rick Rickertsen, a venture capitalist with Thayer Capital Partners, said the technology community as a whole is experiencing a meltdown. He is particularly concerned about one of the companies he's invested in, EPlus, because it has an agreement where PSINet resells EPlus software. EPlus is reporting profits, but it could be adversely affected by PSINet's problems, he said.

"When you've got unhealthy partners like that, it impacts your business," Rickertsen said.

Law Firms Grow Wary Regional economists say that so far the Washington area economy remains strong, with 78,000 new jobs added this year, including 12,000 in the technology industry.

Those numbers notwithstanding, gone are the days of huge run-ups in dot-com stock prices at companies with a stash of venture capital and stock options for the youthful staff.

Tech firms aren't the only ones feeling the effects.

Tysons Corner lawyer Jonathan Forster, who handles tax and estate planning, said some of his high-tech clients are now asking how to protect themselves from potential creditors if they must declare bankruptcy.

"They ask, 'Is there an exemption for life insurance from bankruptcy?' " he said. "When I get asked those questions, I see it coming up."

Forster said law and accounting firms that once leapt at the prospect of getting the business of technology companies have grown warier, asking for cash retainers instead of a portion of the equity of the client company.

John Young, a financial adviser at Legg Mason Wood Walker Inc. in Bethesda, said he was doing as much work as ever but makes less money because his pay is based on his clients' assets. Most of the people he represents in the high-tech industry now find their stock options under water--or at least worth less now than they were even three or four months ago. (The Nasdaq composite index has lost a quarter of its value this year and is down 40 percent from its high in March.)

Clients who laughed off the idea of investing in mutual funds last spring, thinking them "silly or just boring," are rushing to diversify their holdings.

"It creates more work for the same amount of new assets brought in," Young said. "You're working off a lower asset base and doing the same amount of work. You make less for the same work."

David Guernsey, chairman of the Fairfax County Chamber of Commerce, said his Guernsey Office Products Inc. has lost a handful of its 7,200 customers throughout the Washington area this year because the firms went out of business. Now, he said, "we're very careful about extending credit."

Top-level executive recruiters who were once "maniacal" are now "merely busy," said Kerry Moynihan, managing director of the Tysons office of Korn/Ferry International.

"I was getting five calls a day," Moynihan said of his schedule at the height of the tech recruiting boom. "I felt like the chap who's won the lottery. 'Remember you sat next to me in social studies in high school? Can you do a placement for me?' It was too crazy."

FBR's Riechers said he was less concerned about silly Internet dot-coms going out of business than the current troubles of one of the nation's first Internet companies, PSINet.

"PSINet is a foundation of both our technology community and the Internet community," Riechers said, adding that the firm's chairman, William L. Schrader, "has been a forward-thinker. . . . There's a fundamentally valuable business there."

Still, he said PSINet's woes send a clear message to technology companies that viable business or not, capital won't always be available. "It is a warning post about the rate at which they raised capital and consumed capital," Riechers said. "Very large companies and very small companies are learning that lesson."

Peter Barris, managing general partner of the Reston office of venture capital firm New Enterprise Associates, said one of the companies NEA has invested in has a new deal with PSINet, raising questions about the fate of the partnership. It's the sort of concern that has become increasingly common over the past few months, Barris said.

"Now, as we sit in board meetings, it is raised--and it never was before--can we count on this business?" he said.

PSINet was not supposed to be the kind of company to raise such questions. It had built a reputation as a highflier after it agreed to pay up to $110 million over 20 years for the rights to name Baltimore's football stadium in the Inner Harbor. Barris said he was shocked at the news last week that Schrader's 11 million shares of PSINet stock are being seized by the Bank of America to cover his $25 million personal line of credit.

"What a bloody disaster," Barris said. "He's certainly a risk-taker, isn't he?"

Net's Loss, Biotech's Gain But the effects of the dot-com meltdown are not all negative.

Late last year, as investors grew increasingly nervous about the valuations of Internet stocks, money started moving into shares of the biotechnology industry, an alternative parking place for technology investment capital. The shares began a wild run-up that peaked in early March, with some companies' stocks increasing 10-fold or more in three months.

The shares took a big hit in late March after remarks by President Clinton and British Prime Minister Tony Blair raised concerns about potential changes in laws governing gene patents. But the flap blew over in a month or so and many stocks recovered, though few have hit their March peaks again.

Even in the recent market turbulence, many investors continue to see biotech as a bright spot. Initial public offerings and supplementary offerings of biotech shares have been well received almost all year. For instance, InforMax Inc., a Rockville company that writes software to help biologists understand genes, raised about $85 million last month in a successful market debut. The stock gained 33 percent on its first day of trading.

Jay Olshonsky, managing director at real estate brokerage firm Inc., said demand for office space in Northern Virginia is still so high that when dot-coms or other companies go out of business, landlords have little trouble finding new tenants.

"We hear all kinds of stories of dot-coms going out and stronger rents coming in," he said.

Philip Dearborn, president of the Greater Washington Research Center, said the difficulties faced by dot-com companies are "creating some turmoil for people directly affected, if they lost their fortunes or their jobs. But I haven't seen any indication that the big giants are in trouble, like AOL, which would be a problem. The dot-coms will come and go. I just don't think that they're a major presence in the overall economy."

Similarly, Stephen S. Fuller, a regional economist at George Mason University, noted that the region is still adding jobs. "Every sector has failures," he said. "There's no measurable effect in the short term."

Staff writers Dina ElBoghdady, Justin Gillis, Shannon Henry, Carrie Johnson and Jackie Spinner contributed to this report.