Instead, Finns Tero Lehterä and Sami Hirvonen take over after Paananen and his assistants Patrik Fagerlund and Robert Nordmark.
Earlier in the season, sports manager Patrik Zetterberg was also fired and replaced by Niklas Johansson who came from the SHL and Örebro.
The change comes after a difficult season that got even worse after two losses in the space of a day against AIK at the weekend.
Västerås, whose goal was to challenge for an SHL place, is outside the playoffs in eleventh place and is only two points above the qualifying mark.
Lehterä, who won World Cup gold and Olympic bronze as a player, was the head coach of FM league team Saipa for four years and last job was at Slovakia’s Dukla Trencin last season. The contract with 50-year-old Lehterä and Hirvonen runs until the end of the season.