Spectral holeburning by population storage in the Zeeman sublevels of Nd3+ in LaF3 has been demonstrated at 1.8K. From the position of the holes and antiholes the g-values of the lowest components of the 4I9/2 and 4G5/2 manifolds are separately determined to be 2.41 and 1.07, respectively. Hole recovery is due to spectral diffusion between different Nd3+ ions in the ground state. In LaCl3:Nd3+ on the other hand, population is stored in the long lived 4I11/2 metastable state. © 1988.