ldds/WorldCom, Tulsa, OK, likes the software it uses to monitor its 20,000 miles of fiber cable so much that it has entered an agreement with the developer, InvenSys Corp., Houston, TX, to market it. The companies have joined to create InvenSys Ltd., also of Houston, which will offer the real-time network management software to telecommunications carriers. Terry Lindsay will serve as president of InvenSys Ltd.