For multiproduct firms, data on aggregate input usage are typically available but data on activity-specific inputs are not. The present study proposes a generalized cross-entropy approach to estimate activity-specific input allocations that are consistent with the aggregate information. The proposed method does not require behavioral assumptions (e.g., profit maximization) but does accommodate behavioral restrictions as well as nonsample information about the plausible factor shares across enterprises. Monte Carlo experiments using simulated data for multifactor-multiproduct firms are used to evaluate the performance of the proposed method. Copyright 1998, Oxford University Press.