Frontier Airlines has filed paperwork to once again trade its shares on the public market, the first initial public offering by a U.S. airline in more than three years.

The Denver-based airline's parent company, Frontier Group Holdings Inc., filed a registration statement Friday with the Securities and Exchange Commission for an IPO.

Frontier indicated an offering size of $100 million -- a token amount used to determine filing fees that will change later.

It says it will trade under the ticker symbol "FRNT."

Read more at Denver Business Journal.