The Zanzibar government has announced that 10 foreign companies have shown interest in bidding for a project to overhaul and expand Zanzibar's international airport at a cost of $30 million.

The airport on the semi-autonomous islands is important in bringing in tourists, whose spending forms much of the archipelago's economy which also contributes significantly to mainland Tanzania's revenues.

Deputy Minister for Communication Machano Khamis Othman said the 10 companies were vying for the project after the Zanzibar government's decision to rescind a contract awarded to a Chinese company for poor performance in July.

"We are very far back on our schedule. It is hard to catch up but we want to start straight away," he told Reuters late on Friday. He did not give any deadlines.

The qualifying companies include Strabag AG of Germany, Koop B.V. of the Netherlands, Rumdel Construction (Pty) Limited and Group Five International, both of South Africa, and Sogea Satum of France.

Others are Stirling Civil Engineering, Cogel Spa, and Prismo Universal Italiana, of Italy. The others are China Road and Bridge Corporation and Beijing Construction Engineering Group, both from China, Othman said.

The Zanzibar airport runway is being extended to allow larger planes at a time the annual tourist target flow is expected to increase from the current 125 000 per year to 200 000 by 2010, according to government projections.