PORTLAND, Ore., June 4 -- Alcatel said it would close its Portland underwater cable manufacturing plant this year and lay off 480 employees. According to an Alcatel spokesperson, about 100 have been dropped already and the remainder will be phased out as Alcatel closes the plant by the end of this year. Alcatel had announced Tuesday that it expects a second-quarter loss of $2.6 billion due to an industry downturn. Alcatel also has underwater cable plants in France and Australia, which have newer machines and will be kept running.