Hundreds of Australian travel agents are claiming several carriers have shortchanged them by not paying commissions on fuel surcharges, resulting in the filing of a suit in Federal Court on Friday. The suit claims Air New Zealand, British Airways, Cathay Pacific, Malaysia Airlines, Singapore Airlines and Qantas Airlines breached the Trade Practices Act by requiring agents to book fuel surcharges in the commission-free taxes, fees and charges section of air tickets. Agents are claiming the unpaid commissions date as far back as May 2004.