Our ratings on Japan-based telecommunications service provider Nippon Telegraph&Telephone Corp. (NTT; AA/Stable/A-1+) reflect its "excellent" business risk profile--backed by an overwhelming lead in Japan's fixed-line, mobile, and broadband markets--and major subsidiary NTT DOCOMO Inc.'s (AA/Stable/A-1+) almost 50% share of the mobile market, a highly profitable pillar of its earnings. In the broadband business, NTT is also by far Japan's largest fiber-to-the-home (FTTH) services provider. Furthermore, we also factor into the ratings increasing earnings from NTT's system integration (SI) business and a "minimal" financial risk profile backed by strong cash flow. Constraints on the ratings include slowing gains in net subscriptions in its FTTH services and mobile business owing to intensifying competition. NTT group dominates telecommunications subscriptions in Japan,
