  Motivated by the problem of understanding 3-point correlation functions of
gauge-invariant operators in N =4 super Yang-Mills theory we consider
correlators involving Wilson loops and a "light" operator with fixed quantum
numbers. At leading order in the strong coupling expansion such correlators are
given by the "light" vertex operator evaluated on a semiclassical string world
surface ending on the corresponding loops at the boundary of AdS_5 x S^5. We
study in detail the example of a correlator of two concentric circular Wilson
loops and a dilaton vertex operator. The resulting expression is given by an
integral of combinations of elliptic functions and can be computed analytically
in some special limits. We also consider a generalization of the minimal
surface ending on two circles to the case of non-zero angular momentum J in S^5
and discuss a special limit when one of the Wilson loops is effectively
replaced by a "heavy" operator with charge J.
