THE management contract for Macau airport will go up for tender this week, with international interests competing with a Portuguese-Chinese joint venture that has all the political advantages. The multi-million dollar contract has been opened to public and private interests, who will be bidding for the right to manage most of the airport's operations. Director of the Macau International Airport Company (CAM), Elsa Sousa Serreira, admitted that a joint venture between the China-supported Macau Air Services Company and Portugal's Aeroportos e Navegacao, which was set up last month to bid for the tender ''has an important political advantage''. ''But if we receive interesting proposals [from other companies] we might ask them to join the project.'' It was most likely a non-Portuguese or non-Chinese concern would be invited in as a third partner, rather than getting the full contract. CAM chairman Diogo Pinto said the operations for the management company would include air-traffic control, most airport security and fire fighting, car-parks, road access and a waste-disposal plant. ''We have the franchise to build and to operate the airport; we are working hard on the building side, but as for operating, it makes sense to subcontract,'' he said. There had been at least seven applications by overseas companies in Britain, the US, Portugal, China, Holland, Singapore and Australia. He said companies or public operators in Hong Kong had shown no interest. This was confirmed by the Provisional Airport Authority and the Civil Aviation Department. CAM was discussing security with the Macau Security Forces, which has set up a anti-terrorist taskforce for the future airport. Professor Pinto said the island had been formed and compacted, and work would begin next month on the pavement and apron area. The airport was still on target to be completed next summer, with test landings scheduled from June. It would open as soon as it had passed international airport safety standards. The airport is anticipating an average of 40 landings a day in 1996, increasing to about 120 a day by 1998.