The Panama Canal Authority is offering shippers a more flexible system for booking passage through the waterway so that customers can better align transit with changing market conditions. The change will enable shippers to adjust their schedules based on shifting cargo volumes, seasonal demand or strategic changes in their fleets. Under normal conditions, the Panama Canal handles about 3% of global maritime trade volumes. Customers can now reserve transit dates up to 15 days in advance, and higher bids will give customers better access to date selections, the authority said. The canal authority is also reinstating an advanced access rule for liquefied natural gas, or LNG vessels, that operate under strict delivery schedules.