Gauging isometries on hyperkahler cones and quaternion-Kahler manifolds

We extend our previous results on the relation between quaternion-Kahler ma nifolds and hyperkahler cones and we describe how isometries, moment maps a nd scalar potentials descend from the cone to the quaternion-Kahler space. As an example of the general construction, we discuss the gauging and the c orresponding scalar potential of hypermultiplets with the unitary Wolf spac es as target spaces. This class includes the universal hypermultiplet. (C) 2001 Published by Elsevier Science B.V.