The instant invention relates to a process for increasing the viscosity of organic liquids by incorporating in said liquid a minor amount of polymer complex, and 1 to 1000 parts per million by volume of a cosolvent for the ionic groups of said polymer. The polymer complex comprises the reaction product of a metal neutralized sulfonated polymer and a styrene-ring pyridene copolymer, wherein the polymer complex is substantially soluble in said organic liquid, and pendant sulfonate groups which are substantially insoluble in said organic liquid. The cosolvent is selected because it will solubilize the pendant sulfonate groups and provide a reasonably homogeneous mixture of solvent, cosolvent and ionomeric polymer. The preferred compositions prepared by the method of the instant invention comprise an organic liquid having a solubility parameter of from 6 to 10.5 in combination with a polymer complex containing from 0.2 up to 10.0 mole % sulfonate groups which has been neutralized by a basic material selected from Groups IA and IIA, IB and IIB of the Periodic Table of Elements (and also lead, tin and antimony) and 1 to 1000 parts per million by volume of a nonvolatile alcohol or amine cosolvent.