Asia's largest biennial air show begins here on Wednesday with international defence and aerospace companies seeking to raise the sales pitch, pursuing multi-billion dollar contract opportunities in India. The five-day Aero India 2009, held at Indian Air Force station Yelahanka, would see participation of 592 companies from 25 countries, 303 international and 289 Indian. Significantly, the participation of domestic exhibitors has steadily grown from 66 in its inaugural show to 289 in this seventh edition, accounting for nearly half the total exhibitor strength. For the first time, China would participate in the show with a 10-member delegation, led by the Deputy Chief of Chinese Air Force.