With the government on hold, so are many critical tech industry discussions and proceedings. The Capitol building stands behind a fence in Washington, D.C., U.S., on Wednesday, April 6, 2011. (Andrew Harrer/Bloomberg)

The thinned speaker list was one of several examples of how the government shutdown has been affecting the tech world at a major industry conference this week in Washington.

The shutdown made no-shows of acting Federal Communications Commission chairwoman Mignon Clyburn and Rep. Doris Matsui (D-Calif.), who were scheduled to speak Wednesday during the annual Telecommunications Industry Association conference.

The same was true of National Institute of Standards and Technology director Patrick Gallagher and the State Department’s Daniel Sepulveda, who also cited the shutdown in their regrets to the TIA.

And it peppered the comments of policymakers and officials who did attend, including Rep. Marsha Blackburn (R-Tenn.), who opened her tech policy speech Wednesday with a long condemnation of the political stalemate that has furloughed 800,000 federal workers and significantly curtailed or suspended government services.

“We are in the middle of a government slowdown right now because of the stubborn refusal of the White House and our colleagues in the United States Senate to work with the House,” said Blackburn, before moving on to issues such as cybersecurity and telecommunications regulation.

Those walking past booths and pockets of conversation at the event, found it hard to go more than a few steps without hearing mention of the shutdown. And though lobbyists joked that there was no one around for them to talk to in the past week, the mood was heavy, as several firms complained that the shutdown has put the brakes on important company and industry-wide projects.

“It’s already hurting companies,” said Grant Seiffert, the president of the TIA, whose organization sets industry standards and counts a wide range of device and networking companies such as Cisco, Dell, Apple, and Nokia Solutions and Networks, as members. He said TIA member companies have told him that holdups at federal agencies have delayed equipment approval and, consequently, companies’ ability to send things to the market.

“Especially going into the holidays, it’s a big deal,” Seiffert said. “And customers may not want to wait for the catch-up.”

The shutdown has also put the operations — and Web sites — of agencies critical to the tech industry, such as the FCC, largely on hold. Companies, often already frustrated with pace of government bureaucracy, are not able to file paperwork and are left wondering about the timeline on decisions critical to their plans for the future.

Those include guidelines for spectrum auctions scheduled to start next year, several speakers at the conference said, as well as ongoing talks about setting up a program to allow the public and private sectors to share more cybersecurity data.

Cybersecurity efforts are particularly time-sensitive. The fallout from reports on the National Security Agency’s surveillance programs has already hurt telecommunications businesses, Seiffert said, and eroded the trust that companies have built with their clients — particularly clients based overseas in places such as Brazil.

“It impacts potential sales and who buys what from where,” Seiffert said.