LONDON and PITTSBURGH, June 10 -- Marconi announced it has signed an agreement with Ericsson to source Marconi's dense wavelength division multiplexing (DWDM) next-generation optical networking equipment, encompassing the companies' well-established agreement on synchronous digital hierarchy (SDH) equipment. The new agreement is effective immediately. Ericsson will also provide services to Marconi's optical network customers, including network management solutions developed in-house. The agreement is subject to regulatory review where required.