Its private equity owner Onex has hired Goldman Sachs, Credit Suisse and Bank of America as global coordinators for the listing, the sources said.

The banks declined to comment while Onex was not immediately available for comment.

SIG makes cartons for beverages and food and competes with larger rival Tetra Pak, a unit of Tetra Laval. It is expected to report earnings before interest, tax, depreciation and amortisation (EBITDA) of about 450 million euros this year.

New shares worth up to 1 billion euros may be offered in the flotation, one of the people said, adding that on top of that existing shares worth up to 500 million euros may be sold.

The bulk of the proceeds will be used to bring down debt levels from a current 5.5 times EBITDA to about 3.5 times, the person said.

Ahead of the listing, Onex will also sound out potential buyers for the firm it bought in 2015 from New Zealand billionaire Graeme Hart in a deal valued at 3.75 billion euros, the person added.

A listing may value SIG Combibloc at about 9-10 times its expected core earnings, including debt, in line with rivals including Bery (>> Berry Global Group Inc), Ball, Silgan, Bemis or Polyone, the sources said.

In an increasingly crowded European equity-raising market, Switzerland is seeing a flurry of stock market listings, including transport firm Ceva Logistics and drugmaker Polyphor announced on Monday.

SIG had been listed in Switzerland before as part of the Schweizerische Industrie Gesellschaft (SIG) conglomerate that made everything from juice cartons to passenger trains to weaponry. Its businesses were gradually sold off as the company narrowed its to focus to packaging.

Rothschild is acting as an adviser on the IPO, Reuters reported in March. ($1 = 0.8119 euros)

(Reporting by Arno Schuetze; Editing by Douglas Busvine and Jane Merriman)

By Arno Schuetze