ＳＥＣでこういう動きがあったのですね。

http://www.protiviti.com/?epi-content=ARTICLE_VIEW&folderPath=%252FPRO%252Fpro-us%252FSEC_Reports%252F&docName=SECReports_20051214.html&beanStrID=SEC%20Reports&viewID=content:Protiviti　（リンクを貼りなおしました。）

SEC Amends Accelerated Filing Rules and Proposes New Deregistration Rules for Foreign Companies - December 14, 2005
Today, the Securities and Exchange Commission (SEC) adopted rules affecting acceleration of filing deadlines for periodic reports required under the Securities Exchange Act of 1934. The Commission also voted to publish for comment rule proposals concerning (a) the process whereby a foreign private issuer can terminate reporting requirements for classes of its securities registered under the Exchange Act and (b) the best-price rule on tender offers. The SEC press release concerning today's meeting may be found at http://www.sec.gov/news/press/2005-176.htm.

Ｐｒｏｔｉｖｉｔｉのサイトにある情報に目を通しただけですが、Ｅｘｃｈａｎｇｅ　Ａｃｔを読み返してから、改めて読みたいと思います。

プロティビぃティの日本語のサイトはあまり更新が頻繁ではありませんが、本家はこまめに更新されています。