PARIS — International regulators have approved deadline extensions for a group of Latin American countries, including Uruguay and Venezuela, who are planning to build and launch telecommunications satellites but are having trouble meeting the required milestones. Similar waivers were granted to Indonesia for three planned satellites.

Regulators also agreed to a preemptive request by Vietnam to have its satellite in-service date extended in the event of a delay in the arrival of a second satellite that is sharing the same Ariane 5 launch vehicle, or a more-extensive delay should there be a launch failure.

Vietnam’s first satellite, Vinasat-1, is under construction by Lockheed Martin Commercial Space Systems of Newtown, Pa. Lockheed Martin, which is under contract to deliver the satellite in orbit, selected Europe’s Arianespace consortium for a launch in mid-2008 aboard an Ariane 5 rocket that also will carry a second telecommunications spacecraft.

Vietnam had asked the World Radiocommunication Conference (WRC), which met Oct. 22-Nov. 16 in Geneva, to give assurances that the satellite would not lose its orbital-slot reservation, which expires in mid-2008, in the event of a launch delay.

WRC delegates agreed that “in this singular case,” an extension to May 2009 in the event of a delay caused by Vinasat’s co-passenger, and to May 2011 in the event of a launch failure.

The situation was more complicated in Latin America. Uruguay had reserved the 78 degrees west longitude slot in November 1999, with the usual seven-year deadline for bringing the system into use.

Unable to develop the satellite, and with the November 2006 deadline approaching, Uruguay struck a joint-venture agreement with Venezuela. What was once called Urusat-3 became Venesat-1, to be used by both nations. Venezuela has contracted with the China Aerospace Corp. for the construction and launch of the satellite, now scheduled for August 2008.

The WRC agreed to the new plan, giving the project a Nov. 15, 2008, deadline.

In making its case to the regulators, Uruguay said its economic crisis in 2001 had prevented it from financing the satellite on schedule.

The United Nations-affiliated International Telecommunication Union (ITU), whose governments meet every four years at WRC, has long sought to bring discipline to the filing of satellite reservations to assure that orbital slots and broadcast frequencies are not left unused.

But the ITU’s rules also call for regulators to take into account “the special needs of the developing countries” to assure that these nations’ poverty or disorganized bureaucracies do not keep them from having access to their share of the limited spectrum and geostationary orbital slots.

Venezuela and Uruguay also argued that the Venesat-1 is under construction, with much of the financing already committed.

A similar situation occurred with a satellite called Simon Bolivar-2, a project long backed by a group of Andean nations at 67 degrees west longitude. The deadline for beginning operations of this satellite was Sept. 18, 2005.

These Andean Community nations, including Colombia, Equador, Peru and Bolivia, had told regulators that “problems of a financial nature and changes in the satellite telecommunications market have made it difficult to comply with the deadlines.”

They also cited “problems essentially of lack of resources and expertise characteristic of developing countries, and changes in the satellite telecommunications market related to the dominance of a small number of large firms” in pleading their case to WRC delegations.

The deadline for beginning operations of the Simon Bolivar 2 satellite at 67 degrees west was therefore extended by five years, to Sept. 18, 2010.

Indonesia had missed deadlines for filing paperwork related to three satellite orbital slots, at 107.7, 113 and 150.5 degrees east longitude. When the filings were sent to regulators – about three years late – they were rejected.

Indonesian authorities appealed to the WRC to reinstate the filings, saying that the delays were caused by miscommunication between Indonesia’s satellite operators and the government authorities responsible for communicating with regulators. WRC delegates agreed that the seven-year clock for the three slots would start from the date that the modified Indonesian reservations were received – in February 2006, December 2006 and October 2007.

With their rights to the slots now reinstated, Indonesian government authorities said they will make a fresh evaluation of how they allocate orbital frequencies to private-sector operators including PT Telkom and PT Indosat.