The initial price of the shares was 68 francs but investors bid the price up beyond 70 francs in early morning trading.
The IPO was the biggest on Switzerland’s stock exchange since 2006 , Sunrise said.
The company said that because of strong demand for shares from a “broad range of institutions” it decided to increase its offering by five million shares.
British investment company CVC Capital Partners, which controlled 90 percent of Sunrise when it was privately held, is expected to see its stake reduced to as little as 25 percent through the share offering.
The offering consisted of 20 million new shares issued by the company and 9.3 million shares offered by the selling shareholder.
A syndicate of banks has been offered an option to acquire 4.1 million additional existing shares until March 8th.
Sunrise said it plans to use 1.36 billion francs in proceeds from the IPO to “substantially strengthen its balance sheet and exploit future growth opportunities”.
With 2.5 million mobile and 400,000 land-line customers, the company is the second biggest telecom in Switzerland behind dominant player Swisscom and ahead of Orange.
Sunrise generated total revenues of two billion francs in 2013.