STOCKHOLM, Saturday, April 27--French Foreign Legion troops from Africa were reported in frontier dispatches early today to have driven the Germans back "with heavy losses" to the north of Trondheim while Allied troops and planes battled Nazi motorized columns south of the strategic Norwegian seaport.

The Norwegian High Command claimed that one of the Germans' two pounding drives up through central Norway--the one up the Gudbrands Valley to a point about 120 miles directly south of Trondheim--had been halted 35 miles south of Dombaas, communications hub and a key to Trondheim.

Nazis Checked in Valley

The other Nazi force driving northward up the Oester Valley nearer the Swedish border, appeared to be encountering fierce and stubborn opposition from reinforced British and Norwegian forces.

The Germans in the Oester Valley were pushing from Roeros, behind bombing and machine-gunning planes blazing a path, toward the British base at Stoeren.

The Aftonbladet's correspondent re- ported that the Germans north of Roeros were finding the going increasingly more difficult in the rugged region as British fighting planes, operating from new Norwegian bases, appeared and gave battle to the Nazi bombers