NAIROBI (AFP) - Leaders from Africa's main trading bloc met Tuesday at a Kenyan summit to discuss ways of enhancing its free trade zone, including steps to a customs union, amid widespread regional tensions.

Nine heads of state and government attended the two-day summit, which caps a 12-day meeting of the Common Market for Eastern and Southern Africa (COMESA).

Kenyan President Mwai Kibaki, who took over the reins of the bloc from outgoing chairman President Ismail Omar Guelleh of Djibouti, lauded advances made towards a customs union, set to be launched at the end of next year.

"Kenya has taken over the chairmanship of COMESA at the time when we have made a major step forward in the journey towards establishing a customs union," Kibaki said, after trade ministers last week agreed on a common external tariff system.

The deal recommends that countries allow free movement of capital goods, introduce a tax of 10 percent for intermediate products and 25 percent for finished goods.

The 19-member bloc, representing around 400 million people, plans to launch a customs union in December 2008, but experts say the deal may be delayed by some member states who fear their weaker economies could collapse.

When it was founded in 1993, COMESA aimed for a free trade zone for all member countries from 2000, evolving into customs union by 2004 and monetary union by 2025.

But it has fallen short of its plans, with the

Democratic Republic of Congo, Ethiopia, Eritrea, Seychelles, Swaziland and Uganda yet to participate in the free trade zone and balking at the customs union. 

The Kenyan president also called for closer ties with other regional economic communities, including the South African Development Community and the East African Community, to assist in negotiations with the

European Union and the

World Trade Organization. 

The leaders also discussed regional peace and security.

"The promotion of peace and security within the region is a precondition necessary for the development of trade but also for ensuring an environment for attracting and protecting investment," said outgoing chairman Guelleh.

He called for international aid to help create peace in war-torn Somalia ahead of a reconciliation conference planned for mid-June.

"We need to put in place an emergency programme that will assist while we conclude the political process," he said.

A report discussed by the bloc's foreign ministers called on Ethiopia and Eritrea to scale down tensions over their disputed border. It also urged Sudan to work with the African Union and the

United Nations over its volatile Darfur region. 

However, there was no censorship of Zimbabwean President Robert Mugabe, the target of much international criticism over his recent opposition crackdown.

Mugabe was named vice chairman of COMESA during the meeting.

Prime Minister Meles Zenawi of Ethiopia, Rwandan President Paul Kagame, Sudan's Vice President Salva Kiir, Ugandan President Yoweri Museveni, and Zambian President Levy Mwanawasa also attended the summit at the UN headquarters in Nairobi.

COMESA groups Burundi, Comoros, the DRC, Djibouti, Egypt, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Malawi, Mauritius, Rwanda, Seychelles, Sudan, Swaziland, Uganda, Zambia and Zimbabwe.