France's Veolia Water, the world's largest water company, will fully enter the Japanese waterworks market by boosting its stake in a Japanese partner, a newspaper said Sunday.

Veolia Japan Water KK, a subsidiary of the French firm, has recently upped its stake in Nishihara Environment Technology Inc, a waterworks firm, to 51 percent from the 20 percent it acquired in 2006, the Nikkei business daily said.

With the purchase, Veolia Japan sent a president to Nishihara Environment, now capitalised at 1.4 billion yen (13 million dollars), as a first step to its full entry into the Japanese waterworks market, the newspaper said.

Japan's waterworks market was liberalised in 2002 when a legal revision allowed local governments to outsource waterworks operations as part of the nation's structural reforms.

Nishihara Environment is currently engaged in water-related business for municipalities, such as construction of waterworks facilities and human waste treatment plants.

The Tokyo-based firm posted sales of about 15 billion yen for the year through March 2006.

Veolia hopes to expand its business in Japan by combining its know-how in operating water facilities and Nishihara Environment's nationwide network and connections to public-sector clients, Nikkei said.

In Japan, Veolia has separately been engaged in water treatment plant operations and sewage plant maintenance by cooperating with Japanese partners, Electric Power Development Co.