NEW YORK, Jan. 4 -- Metromedia Fiber Network has signed a third dark-fiber lease agreement with Allegiance Telecom. Metromedia Fiber estimates the agreement to be worth approximately $130 million over its 20-year life. Previously, Allegiance acquired fiber capacity on Metromedia Fiber's networks in the Dallas, Houston and New York metropolitan areas.The agreement calls for Metromedia Fiber to lease local dark fiber infrastructure to Allegiance in the following metropolitan areas: Chicago, Boston, New York, New Jersey, Philadelphia, Washington, Atlanta, Los Angeles/Orange County, San Jose, Calif., San Francisco/Oakland, and Seattle. In addition, Metromedia Fiber is to provide Allegiance with long-distance fiber capacity between New York and Washington.