The Panama Canal Authority (ACP) is offering more opportunities for shippers to outbid each other for a dwindling number of transit slots on the drought-impacted waterway, but most U.S. LNG traders appear to be avoiding the route altogether.

After announcing late last month that the number of available passages through the canal would be reduced even further for the rest of the year, ACP has launched a series of special auctions for additional transit slots.

ACP hosted its first sale Saturday, offering ships that have queued off the coast of Panama for at least 10 days but haven’t been able to schedule their crossing a chance to bid on a slot. Initial bids for the auction started at $55,000.

“The purpose of this measure is to provide greater opportunity of obtaining a...