Groupon Inc., the largest online-coupon site, filed to raise as much as $540 million in its initial public offering.

The Chicago-based company is offering 30 million shares of Class A common stock at $16 to $18 each, according to a regulatory filing today. That compares with the $750 million Groupon filed to raise in June. The stock will trade on the Nasdaq Stock Market under the symbol GRPN.

Since filing to go public, Groupon has drawn regulatory scrutiny, restated results and lost executives. The company delayed plans to pitch the offering to investors in September amid stock-market swings, according to people with knowledge of the matter, and also needed extra time to address revisions to a controversial accounting method used in its prospectus.

The company is set to meet with investors as soon as the week of Oct. 24 to gauge demand for the IPO, people familiar with the matter said, a process that usually lasts for about two weeks before completion of an initial offering.

Groupon’s IPO would be the fourth in the U.S. since the beginning of September as slumping stocks and high volatility made it difficult to bring offerings to market. Still, companies have continued to file for offerings this year, leading to the biggest U.S. backlog in a decade as of the end of last quarter, according to Renaissance Capital LLC, the Greenwich, Connecticut-based IPO research and investment firm.

Morgan Stanley, Goldman Sachs Group Inc. and Credit Suisse Group AG are leading Groupon’s offering.