model selection with spg and AIC (or, convert list to fitted model object)

Dear R Help,

I have two nested negative log-likelihood functions that I am optimizing 
with the spg function [BB package].  I would like to perform model 
selection on these two objective functions using AIC (and possibly 
anova() too).  However, the spg() function returns a list and I need a 
fitted model object for AIC(), ICtab() [bbmle package], or anova().

How can I perform AIC-based model selection on two spg-optimized 
objective functions?  Alternatively, how can I convert the list returned 
by spg into a fitted model object that can be run in AIC, ICtab, or anova?