The class 842 is a four-axle diesel railcar built for regional service on non-electrified mainlines. It is being powered by two six-cylinder diesel engines which drive the inner axle of each bogie. Two prototypes were built in 1989 which were designated M 274.2. After the collapse of Czechoslovakia, a revised variant was placed into production at Vagonka Tatra Studénka in what was now the Czech Republic. This was now designated class 842 according to the new scheme.

The production variant still had the same LIAZ engines, but the transmissions now came from Allison instead of Praga. Production switched to the more modern class 843 after 35 had been produced. They are being used together with driving trailers and various older trailer cars. In 2012, they were modernized with more powerful Tedom engines and five-speed ZF gearboxes.