A new class of generalized convex set-valued functions, termed nearly-subco
nvexlike functions, is introduced. This class is a generalization of cone-s
ubconvexlike maps, nearly-convexlike set-valued functions, and preinvex set
-valued functions. Properties for the nearly-subconvexlike functions are de
rived and a theorem of the alternative is proved. A Lagrangian multiplier t
heorem is established and two scalarization theorems are obtained for vecto
r optimization.