EXTENSIONS OF p-LOCAL FINITE GROUPS
C. Broto, N. Castellana, J. Grodal, R. Levi, and B. Oliver

A $p$-local finite group consists of a finite $p$-group $S$, together with 
a pair of categories which encode ``conjugacy'' relations among subgroups 
of $S$, and which are modelled on the fusion in a Sylow $p$-subgroup of a 
finite group.  It contains enough information to define a classifying 
space which has many of the same properties as $p$-completed  classifying 
spaces of finite groups.  In this paper, we study and classify extensions 
of $p$-local finite groups, and also compute the fundamental group of the 
classifying space of a $p$-local finite group.