Simple four probe resistance measurements have been used to study the ligand exchange between monolayer protected clusters of Au and Ag with dithiol monolayers on planar gold surfaces. The decrease in in-plane resistance upon exposure of functionalized dithiol monolayer covered gold surfaces to monolayer protected cluster solutions is attributed to the attachment of free thiol groups of the monolayers on the gold surfaces to the clusters. This linking of clusters to monolayers results in screening of electron-adsorbate vibration interaction causing a decrease in resistance. There can also be additional factors determining the observed changes.