Japan Post Holdings, which is 100-percent controlled by the government, runs a network of more than 20,000 post offices as well as the country's biggest banking and insurance operations.

The Nikkei business daily reported that the government plans to release some 10 percent of the outstanding shares of each unit in an initial public offering (IPO).

The group's net assets are estimated to stand at around 14 trillion yen ($116.73 billion). The three units could be valued at up to 700 billion yen, according to the newspaper.

Announcement as early as Friday

Japan Post president Taizo Nishimuro will hold a press briefing on Friday, when the offering will be announced, according to the Reuters news agency, quoting sources familiar with the situation.

The privatization of the postal service has been in the works since 2005, but was stalled when the Liberal Democratic Party lost power in 2009. Now the party is back in power, it is expected to press ahead with the IPO plans.

The government plans to use some of the proceeds from the IPO for reconstruction work after the country's 2011 earthquakes.

ng/bk (Reuters, AFP, dpa)