African nations are looking to boost their exports to key markets
The five countries that make up the East African Community have agreed a plan that will gradually open their markets to the European Union (EU).
Kenya, Uganda, Tanzania, Burundi, Rwanda are covered by the EU deal.
The new agreement will replace preferential trade obligations, which are due to expire in December and have proved controversial in recent years.
A number of other nations in Western Africa, and some Pacific nations, have yet to accept the new arrangements.
The East African Community (EAC) trading bloc has agreed to "gradually open their markets to goods from the EU over a period of 25 years", an EU official said.
Despite giving European firms more access to their markets, some industries will still be protected from competition to prevent local businesses from going bankrupt.
Under the terms of the new deal, about a fifth of EAC trade would still be exempt from the requirement to lower customs duties.
Industrial products and agriculture are among the sectors that are to be given extra protection.
The EU said that negotiations would continue next year in an effort to have a more comprehensive Economic Partnership Agreement in place by 2009.
The new deals will replace earlier preferential trade obligations that linked the EU and many of its trading partners but which have been heavily criticised by other nations, particularly those in Latin America.
The deals have been ruled illegal by the World Trade Organization and the 27 members of the trade bloc have until the end of the year to establish new arrangements with partners.
But it is not thought that all 80 nations in Europe's former African, Caribbean and Pacific colonies will have signed up to the EPAs by 1 January because there is still a lot of opposition to the deals.
Critics argue that the EPAs could damage developing economies by cutting their customs revenue and making it harder for local businesses to compete with larger foreign rivals.