We show in a general mixed model the best linear unbiased estimators (
BLUE) of fixed effects, with unknown variance components substituted b
y the REML estimates, are jointly asymptotically normal with the REML
estimates. We also prove that given sufficient information the empiric
al distributions of the best linear unbiased predictors (BLUP) of rand
om effects, again with REML-estimated variance components, converge to
the true distributions of the corresponding random effects. As a cons
equence, we obtain a consistent estimate of the asymptotic variance-co
variance matrix of the REML estimates. The results require neither tha
t the data is normally distributed nor that the model is hierarchical
(nested).