Tokyo -- Standard&Poor's CreditWire 1/4/1999 -- Standard&Poor's today lowered its long-term rating of Nippon Telegraph&Telephone Corp. (NTT) to double-'A'-plus from triple-'A', and removed the rating from CreditWatch, where it was placed on Sept. 29, 1998. The outlook for the long-term rating is stable. NTT's 'A-1'-plus short-term rating, which was not placed on CreditWatch, was affirmed. The downgrade reflects increasing strain on NTT's operating and financial performance under difficult economic conditions and mounting industry competition in Japan. Earnings from the company's core, fixed-line telecommunications business face several challenges, including a slowdown in subscriber growth partly owing to expansion in the cellular market, continued downward pressure on rates, and rising competition in the local network business.