After running the Panama Canal for nearly a century, the United States officially handed over control of the strategic waterway to the Panamanian government today, opening a new era of full sovereignty for this country.

As a giant digital clock counted off the last second of U.S. jurisdiction over the waterway, throngs of Panamanians jubilantly rushed up a soggy grass hill leading to the Panama Canal Commission headquarters, cheering, singing and waving flags under a steady rain. Their national pride was stoked by an unabashedly patriotic ceremony in which the Panamanian flag was raised where the Stars and Stripes had fluttered since the canal opened in 1914.

"We have waited so long that we cannot believe this moment of full independence has finally happened," said Adviel Centeno, 52, a law office administrator. "The American presence brought some good things but many more bad things that affected all aspects of our life, like the feeling that we were a colony that was not given any respect."

President Mireya Moscoso and U.S. Army Secretary Louis Caldera signed a document formalizing Panama's possession of the 51-mile-long canal and vast stretches of surrounding land which had been a fenced-off swath of U.S. military bases and self-contained communities that were home to thousands of Americans outside Panamanian jurisdiction.

"There will be no more fences and no more signs blocking our entrance. The canal is ours and may God bless it," Moscoso said at the ceremony. "At last, Panama has reached sovereignty."

A day of celebration soon got underway in honor of the transfer, which was the culmination of a 22-year process that began in 1977 when treaties were signed by then President Jimmy Carter and the Panamanian leader of the time, Gen. Omar Torrijos, calling for the United States to relinquish control of the 360,240 acres that make up the Canal Zone and the canal at noon today.

Nearly a century after President Theodore Roosevelt exuberantly declared "I took the isthmus," the handover formally altered ties between the two countries that were born 96 years ago when Roosevelt carved out this nation by negotiating Panama's independence from Colombia with an eye to building the canal. In constructing the waterway, Roosevelt sought to fulfill his vision of a maritime path that would both alter the flow of international trade and give the United States naval dominance.

In recent weeks, the last of the U.S. troops who trained in Panama and provided security for the canal for decades have left, closing a chapter that some Panamanians viewed as an occupation. Gone too are the thousands of other Zonians, the people--most of them Americans--who lived in middle-America-style communities within the Canal Zone, a 10-mile-wide strip of land that was increasingly decried by Panamanians as a U.S. colony in the heart of this small nation.

Said Ken Anderson, 55, a third-generation Zonian who was a teacher at Balboa High School, "It is sad for us because it was a way of life, a very close-knit community that was like a company town in the United States. We are leaving behind a piece of Americana."

But even before today's transfer, the past had given way to a changing face in Panama. Howard Air Force Base, which reverted to Panama two months ago, has taken on the appearance of a ghost town, its barracks empty. At the same time, about 1,700 houses in the Canal Zone have been sold and are occupied by their new Panamanian owners.

The Spanish hotel chain Sol Melia is constructing a $25 million, 280-room hotel on the site of the former U.S. Army School of the Americas on the shores of Lake Gatun and a large shopping mall is being constructed in front of Albrook Air Force Base at a cost of $100 million.

Some Panamanians felt slighted by the fact that President Clinton and Secretary of State Madeleine K. Albright had declined invitations to attend a Dec. 14 ceremony symbolically marking the transfer of the canal. And a decision by the United States to lower its flag in a separate ceremony Thursday, rather than at today's event, heightened that sense.

"I think the United States lost an opportunity to shine. Here is the world power handing over a world-class asset to a small Third World country with a chance to show its best principles. But the United States has chosen to downplay it," said Roberto Eisenmann, a founder of La Prensa newspaper who is also an adviser to Moscoso.

Although polls have shown that a majority of Panamanians would have liked some continued U.S. military presence, some groups have been strident in their insistence that no American military return, and have made their opinions known in graffiti around the Canal Zone. At today's ceremonies, hundreds of students staged anti-American demonstrations, chanting, "gringos out" while dragging a mannequin in military attire by its ankles.

In the United States, congressional Republicans have criticized the handover of the canal--which cost more than $350 million and 5,600 lives to complete in 1914--saying Panama has no army and the canal could be vulnerable to Marxist rebels in neighboring Colombia.

[Supreme Court Justice Sandra Day O'Connor refused to block transfer of the Panama Canal from the United States to the Republic of Panama, the Associated Press reported. Judicial Watch, a conservative legal foundation, had applied for a court order that would have temporarily restrained the turnover. The order was denied by lower U.S. courts earlier this week and was taken to the Supreme Court Friday morning. A court official said O'Connor confirmed the denial without comment.]

Since the treaties were signed, Panamanians have gradually assumed greater operational control of the canal and more leadership posts within the waterway's administration. Today, 97 percent of the canal's 9,130 employees are Panamanian. The position of canal administrator has been held by a Panamanian for the last nine years while Panamanians have held four of the nine seats on the board of the canal since 1977.

The government has also been seeking investment in 61,775 acres of the reverted land within the Canal Zone. It has so far signed contracts totaling $1.5 billion--one-third of which is from U.S. companies--for projects over the next five years on 24,710 acres of the property to develop maritime and commercial services, hotels and other tourist amenities, cruise ship ports at both ends of the canal and privatization of existing ones.