  In this paper a class of combinatorial optimization problems is discussed. It
is assumed that a feasible solution can be constructed in two stages. In the
first stage the objective function costs are known while in the second stage
they are uncertain and belong to an interval uncertainty set. In order to
choose a solution, the minmax regret criterion is used. Some general properties
of the problem are established and results for two particular problems, namely
the shortest path and the selection problem, are shown.
