Forests are still disappearing and local communities disregarded by palm oil development despite a plan to put the sector on a sustainable footing, researchers warned as an industry gathering kicked off Thursday.

After conducting 16 case studies in Africa and Southeast Asia, the hubs of the palm oil industry, researchers said in a new book they were disappointed with a joint industry-NGO initiative to reduce the sector's impact.

The criticism came as the group behind the initiative, the Roundtable on Sustainable Palm Oil (RSPO), began its annual meeting in Indonesia.

"Since its founding 8 years ago, the RSPO has adopted good standards, but too many member companies are not delivering on these paper promises," said Marcus Colchester, one of the authors of the book "Conflict or Consent? The oil palm sector at a crossroads".

The RSPO was created in 2004 by members of the palm oil industry with the support of governments and non-governmental organisations such as the WWF to take a voluntary approach to limit the environmental and social impact of industrial farming.

Today it counts major producers of the popular cooking oil and processed food component as members.

The RSPO certifies operations that claim to respect the rights of indigenous peoples and adopt conservation policies.

The organisation also aims to be a mediator for communities who have seen their way of life disrupted by palm plantations and the industry.

But as world demand for palm oil has boomed, it has touched off a land rush. Experts believe production will expand to Latin America in the next decade to meet growing demand.

In Indonesia alone, palm cultivation occupies 10.8 million hectares (26.3 million acres) -- about the size of South Korea -- and projects in the pipeline would occupy another 20 million hectares, or over 10 percent of the national territory.

Growing palm oil is a major source of conflicts, with the Indonesian government counting more than 4,000 disputes over land, according to Colchester.

It has also propelled Indonesia into third place globally for greenhouse gas emissions, following the United States and China, due to deforestation.

The 16 case studies included Indonesia and Malaysia, which between them account for 85 percent of global palm oil output. Also included were Philippines, Thailand, Cameroon, and the Democratic Republic of Congo.

In most cases the RSPO improved dialogue between local communities and producers, said the book's authors.

Certain companies even adapted their practices to take concerns of local communities into account, they added.

"But RSPO-certified companies have not always held to their commitments, especially in respect to the rights of indigenous peoples and local communities," according to the Forest Peoples Programme, one the groups which conducted the case studies.

It pointed to a disconnect between company executives and managers.

"Senior company officials may have committed to the new approach but too often operational managers have failed to respond," said the NGO.

Numerous companies also fail to follow guidelines and often local governments fail to protect communities, added Colchester.

He said they were disappointed with the slow progress and expressed concern some firms use RSPO certification as a marketing ploy.

Colchester also cited the case of the Singaporean giant Wilmar International, which processes 45 percent of the world's palm oil, and is a RSPO member.

When residents of a community on the Indonesian island of Sumatra turned to the RSPO over a Wilmar project, he said the company sold the concession while mediation was under way, thus ridding itself of the problem it had created.