PROCEEDINGS OF THE EDINBURGH MATHEMATICAL SOCIETY, cilt.54, ss.77-89, 2011 (SCI-Expanded)
Let A be a finite group acting fixed-point freely on a finite (solvable) group G. A longstanding conjecture is that if (vertical bar G vertical bar, vertical bar A vertical bar) = 1, then the Fitting length of G is bounded by the length of the longest chain of subgroups of A. It is expected that the conjecture is true when the coprimeness condition is replaced by the assumption that A is nilpotent. We establish the conjecture without the coprimeness condition in the case where A is an abelian group whose order is a product of three odd primes and where the Sylow 2-subgroups of G are abelian.