Oct 30 (Reuters) - AirAsia Bhd AIRA.KL , Asia&aposs largest budget airline, is seeking to raise up to 1 billion ringgit ($305 million) with an Islamic bond programme to fund aircraft and spare part purchases as well as to refinance its debt.The sukuk uses a mudaraba structure, in which assets are managed by a bank on behalf of clients, with income and expenses shared under a pre-agreed ratio. It w