Nippon Telegraph and Telephone Corp. may book a latent loss of up to 550 billion yen this business year due to the depreciated value of Verio Inc., its U.S. Internet wholesale service subsidiary, NTT sources said Monday.

NTT Communications Corp., a wholly owned subsidiary, acquired Verio in September 2000 for 600 billion yen to get in on the information technology boom in the United States and acquire its customer base of mainly corporate users.

But when the IT bubble burst, NTT was left with a latent loss on Verio stemming from the sharp shrinkage in Verio's "goodwill" standing -- its value as a going concern in excess of its asset value, the sources said.