CHICAGO ( TheStreet) -- Executives at daily deal site Groupon remain committed to going public but are unsure about the timing, The Wall Street Journal reported, citing a person familiar with the matter. Federal regulators have been examining the company's initial public offering documents more aggressively than expected, and the volatility in the stock market is holding the company back from introducing its stock, the person told the newspaper. The company's major shareholders, including Capital Group , T-Rowe Price , Fidelity Investments and Morgan Stanley Investment Management, all have indicated they remain interested in the stock, the person said. On Friday, Groupon amended its offering filing to reduce reported revenue for 2010 to $312.9 million from $713.4 million. The filing also included parts of a letter written by CEO Andrew Mason to employees earlier this month that talked of the company's success. The letter was immediately leaked to the press, which could be seen as a violation of Securities and Exchange Commission rules that a company can't make public statements about its stock during the IPO process, the Journal reported. The SEC could require a "cooling off period" for Groupon that could delay its IPO further, according to two people familiar with the matter. -- Written by Joseph Woelfel >To contact the writer of this article, click here: Joseph Woelfel >To submit a news tip, send an email to: firstname.lastname@example.org.