Three Southeast Asian countries on Wednesday signed a multilateral open skies pact for air cargo services that can be expanded later to include other members of the Association of Southeast Asian Nations (ASEAN).

Transport ministers from Thailand, Singapore and Brunei signed the agreement, which is aimed at reducing manufacturing and business costs for companies in the region, such as making it cheaper to transport electronics components and perishables.

''It would help enhance air cargo services in the region, which in turn will greatly benefit the competitiveness of our respective manufacturing sectors,'' Singapore Transport Minister Yeo Cheow Tong said after the signing ceremony in Singapore.

The air cargo services pact marks the first time for any ASEAN member country to adopt a new ''2 plus X'' approach proposed by Singaporean Prime Minister Goh Chok Tong and Thai Premier Thaksin Shinawatra at the ASEAN Summit in Bali in October last year. It enables two or more ASEAN countries to go ahead first with specific projects if other members are not yet ready to jump on board.

Cambodia and the Philippines have also expressed strong interest in joining the pact, which was first been proposed by Singapore and Thailand, but they requested more time to study the agreement further.

The open skies agreement gives national carriers and local cargo flight operators in the participating countries ''complete freedom'' to operate cargo flights without having to depend on negotiations between their governments and bilateral air services agreements.

Currently, there are 10 weekly cargo flights between Singapore and Thailand, according to Singapore's Transport Ministry, but there is no cargo flight between Singapore and Brunei.

As to whether there is any immediate possibility of new cargo flights being added, the ministry's spokeswoman said, ''We will leave it to commercial demand.''

ASEAN transport ministers have endorsed a road map to achieve a limited open skies framework for passenger traffic among them by 2015, a senior ASEAN official source said Wednesday.