WASHINGTON, Nov. 25 (Reuters) – The US government on Tuesday imposed its first-ever punishment against airlines for stranding passengers aboard aircraft, fining three carriers $175,000 for a six-hour ordeal in Minnesota.

Continental Airlines and its ExpressJet Airlines affiliate were fined $100,000, while Mesaba Airlines, a unit of Delta Air Lines, was fined $75,000, the Transportation Department said.

Continental, ExpressJet and Mesaba all reached settlements with the government's Aviation Enforcement Office.

The action served as a sharp reminder to carriers about service just as the busy Thanksgiving Day travel period gets under way.

Regulators found all three airlines violated a law prohibiting unfair and deceptive practices for their roles in the Aug. 8 incident in Rochester, Minnesota.

Forty-seven passengers were stranded overnight aboard a Continental Express plane en route from Houston to Minneapolis that diverted to Rochester due to bad weather.