The Persian Gulf War has brought a surge of activity to a business long known for its potential rather than its sales -- two-way video-conferencing.

Use of video-conferencing links -- which allow people in distant cities to confer over closed-circuit television -- has doubled on the American Telephone & Telegraph Co. network since the beginning of the war, the company reported. US Sprint Communications Co. reported that requests for its international video lines are triple the usual volume.

Video-conferencing had begun to grow in popularity in recent months because of a recession-prompted reduction in corporate travel. But the trigger for the sharp increases in the past week appears to be travel curbs based on fear of terrorism, particularly on overseas travel.

"That has caused them to scramble for alternatives which allow them to carry on their business," said Norman E. Gaut, chairman of PictureTel Corp. of Peabody, Mass., which makes equipment used in the links. "Video-conferencing is really an ideal substitute."

John Champa, who manages an internal video-conferencing system at computer maker Unisys Corp., said inquiries from Unisys offices about using the network have doubled since the first of the year.

Two-way video links between TV news anchors and correspondents in the field have been commonplace for years and are seeing unprecedented use as the gulf war unfolds. For everyone else, the field remains in its infancy.

After AT&T's display of a "picturephone" at the 1964 World's Fair in New York, pundits predicted it would soon replace telephones for Americans at large. High costs and a predilection for personal contact, however, slowed its advance to a crawl.

In the late 1980s, video-conferencing began gaining ground as a business tool because of lower long-distance line prices and advances in equipment, notably gear that "compresses" a video image so that it can be transmitted over a low-cost, low-capacity line.

Cost have come down, but are still considerable. An hour-long meeting between business executives in the United States and France, for example, costs about $1,550 using the Sprint network and studios rented by the hour, according to Sprint.