French energy services group Spie confirmed it was planning a stock market listing this autumn that analysts have said could value the firm at up to 4 billion euros ($5.5 billion).
Spie Chief Executive Gauthier Louette said the initial public offering (IPO) would involve the sale of existing shares and could be accompanied by a capital increase, but did not specify the amount.
The firm provides mechanical and electrical engineering services to help companies and the public sector make facilities more energy-efficient.
It competes with GDF Suez unit Cofely, Dalkia , Vinci Energies and Sodexo .
"We are at the very start of this process, but if there is no major upheaval on the markets, we could consider an IPO for this autumn," Louette told a press briefing on 2013 earnings on Tuesday.
French media reported late last year that Spie was considering a listing in 2014.
Spie - which is owned by private equity firms Ardian (formerly Axa Private Equity) and Clayton Dubilier & Rice and by
fund manager Caisse de depot et placement du Quebec - had 37,000 staff in 31 countries at the end of 2013, the company said.
Its adjusted 2013 operating profit rose 14 percent to 298 million euros as sales rose 11 percent to 4.6 billion euros.
More than half of its sales, 2.4 billion, came from France, another 1.05 billion from northwestern Europe, including the UK, Belgium and the Netherlands.
In June 2013, Spie paid 250 million euros for the facility and energy management business unit of Germany's Hochtief .
($1 = 0.7277 euros)
(Reporting by Matthieu Protard; Writing by Geert De Clercq; Editing by Erica Billingham)