Multicomponent polymer blends involving polyamide6 (PA6), polypropylene (PP), acrylonitrile-butadiene-styrene (ABS) and high density polyethylene (HDPE) with multiwall carbon nanotubes (MWNT) were prepared by melt mixing technique to achieve conducting composites. MWNT were either compounded directly or by employing a masterbatch dilution approach in binary (PA6/ABS), ternary (PA6/PP/ABS) and quaternary (PA6/PP/ABS/HDPE) blends. To facilitate "network-like" structure MWNT were pretreated with either sodium salt of 6-aminohexanoic acid or octadecyl tri-phenyl phosponium bromide. Multicomponent blends with pretreated MWNT utilizing masterbatch dilution approach showed significant improvements in the bulk electrical conductivity as compared to blends prepared by direct addition approach at 2 wt % MWNT content. Phase morphology of these blends revealed co-continuous type of morphology wherein MWNT were found to be selectively localized in the PA6 phase. The hetero-nucleating action of MWNT was manifested in increased crystallization temperature of mainly PA6 phase of the blends indicating preferential localization of MWNT in the PA6 phase. POLYM. ENG. SCI., 51:1987-2000, 2011. (C) 2011 Society of Plastics Engineers