Livedoor Co. has moved closer to taking a controlling stake in Nippon Broadcasting System Inc., a report submitted by the Internet firm to the Finance Ministry showed Wednesday.

The report presented to the ministry's Kanto Local Finance Bureau shows Livedoor had increased its stake in the radio firm to 45.5 percent in terms of voting rights as of Monday.

Livedoor has secured 13.85 million shares, or 42.23 percent of all outstanding shares in NBS, according to the report. The Internet service firm has been trying to take over the AM radio company in a high-profile acquisition battle with Fuji Television Network Inc.

Livedoor continued to boost its stake in NBS almost daily in March, the report shows. The firm aims to form an alliance with the Fujisankei Communications Group.