The battle for control of radio company Nippon Broadcasting System is hotting up - if such a term may be used of the seemingly unemotive world of Japanese business.

Internet upstart Livedoor has increased its stake in NBS to more than 40 percent of voting rights, stepping up pressure on rival Fuji Television Network.

NBS is the largest shareholder in Fuji and had agreed to be taken over by its affiliate. But if Livedoor succeeds in controlling the radio company, it will make its presence known in the Fuji boardroom.

Sources close to Livedoor say the company will continue buying NBS shares and would also consider sending its executives to the radio broadcaster to put it under its effective control.

Fuji has reduced the size of the stake it seeks in NBS from fifty percent to 25.06% and has extended the offer deadline to March 2.

The move is based on a provision in Japan's commercial code which dictates that two companies in a cross-shareholding relationship both lose voting rights in each other once the ownership of one exceeds 25 percent in the other.

Fuji's stratagem is intended to foil any influence Livedoor may attempt to wield over the TV firm as NBS's largest shareholder.

Data sourced from Asahi Shimbun Online; additional content by WARC staff