The Financial Services Agency is mulling another change to the Securities and Exchange Law that would yank exemptions on the reporting of major share transactions, FSA officials said Wednesday.

The Securities and Exchange Law requires anyone with an equity stake of more than 5 percent in a listed company to report the sale of a stake of 1 percent or more to a local finance bureau within five business days of the sale.

But securities companies, investment advisory firms, banks and other entities that frequently trade large amounts of stock are exempt.

This exemption allowed the sale of a 15 percent stake in Nippon Broadcasting System Inc. to evade the public's radar until Tuesday, despite the fierce battle raging between Livedoor Co. and Fuji Television Network Inc. for control of the AM radio company.

M&A Consulting Inc., the investment group led by investor activist Yoshiaki Murakami, a former trade bureaucrat, filed a report with a local finance bureau Tuesday revealing that its stake in NBS had fallen to 3.44 percent by the end of February from 18.57 percent on Jan. 5.

This disclosure has prompted the FSA to reconsider the exemptions, the officials said.

Hideki Kanda, a member of the Financial System Council, an advisory panel to the FSA, told reporters that any problems emerging from the battle should be reviewed.

The problems also include the exemption of off-hours trading from public tender rules. In early February, Internet company Livedoor used off-hours trading to quietly and quickly boost its stake in Nippon Broadcasting to 35 percent.

The government plans to address this by trying to revise the Securities and Exchange Law so that off-hours trading will be subject to public tender rules.