Stretching across some 200 million hectares (494.2 million acres) and six states, the dense forests are home to half of Africa's wild animals -- including gorillas, chimpanzees and forest elephants -- as well as more than 10,000 plant species.

But if deforestation goes on at its present pace, about 70 percent of the forests may be gone by 2040, global conservation group WWF says.

Host President Denis Sassou Nguesso described the region's forests as "a major issue for all humanity" and said he was confident governments would move from words to actions.

WWF welcomed the commitments at the summit but Greenpeace said countries would have to do better at fighting corruption if funds intended for conservation were to be used effectively.

Chirac attended the meeting as France currently chairs the Congo Basin Forest Partnership, an international alliance set up to help the states of the region protect the environment.

"The heritage of the Congo basin is yours," Chirac told eight African heads of state. "It is also of irreplaceable ecological value for the planet. That is why we must be ready to share a part of the cost of its preservation."

As central Africa contains some of the world's poorest countries, activists say the West will have to provide significant funds if protection measures are to be implemented.

TREATY SIGNED

Congo Republic, the Democratic Republic of Congo, Cameroon, Gabon, Equatorial Guinea, Sao Tome and Principe, the Central African Republic, Rwanda, Burundi and Chad signed a treaty committing them to measures to preserve the region's forests.

The treaty pledges action such as cracking down on poaching and encouraging sustainable management of logging concessions. The leaders also created a new cross-border protected area covering regions of Cameroon, Gabon and Congo Republic.

"These agreements mean that park staff no longer have to watch helplessly as poachers in one country escape across the river into another," WWF director general Claude Martin said.

The leaders met to review progress six years after a first summit on the issue in Cameroon's capital Yaounde.

That meeting was hailed by conservationists as the first time African heads of state had got together to commit themselves to protecting the environment, even as their countries face such pressing problems as poverty, disease and armed conflict.

Environmentalists say some progress has been made on the ground since the last meeting but they are divided over how much.

Some point to concrete achievements such as joint patrols by forest guards in border regions, hi-tech monitoring of wildlife and efforts by logging companies to adopt sustainable practices.

But others say these are far outweighed by widespread corruption, poaching and irresponsible or illegal logging.