EssentialMarkets(TM) Inc. and Caterpillar Inc. have joined forces to enable Caterpillar's small- and medium-sized suppliers to integrate into the international manufacturer's e-procurement system. EssentialMarkets is initially working with Caterpillar's suppliers to upload their product catalogs to the Internet, allowing both Caterpillar and its suppliers to interact through Caterpillar's WECAP e-procurement system.