In September 1944 Bulgaria switched sides and declared war on Germany and the command of the Third Army was taken over by General Asen Krstev. Due to different concerns of the government this army did not directly take part in the fighting, instead it was tasked with the formation and training of different units that were later sent to the front and especially to the Bulgarian First Army. A notable example was the Third Army's 3rd Infantry Division which took part in the Battle of the Transdanubian Hills as part of Operation Frühlingserwachen.