Zain Bahrain, the island's No 1 telecom operator by subscribers, will launch its long-awaited stock market flotation by the end of June, an industry source told Reuters, in what could be the kingdom's biggest share sale since 2010.

Bahrain's Telecommunication Regulatory Authority (TRA) last April instructed Zain Bahrain, 56.3 percent owned by Kuwait's Zain, to sell 15 percent of its shares in an initial public offering (IPO) and list on the local market by the end of 2013.

This deadline passed without comment by the companies or the regulator, but Zain Bahrain has now applied to the Ministry of Industry and Commerce for approval to become a public company, the source told Reuters, declining to be identified because the matter was not yet public.

The company will publish details of the application in the ministry's gazette and must then wait 60 days for any objections to be lodged, although that is largely a procedural formality, the source said.

After that, Zain Bahrain can launch its IPO. It shelved a previous plan to go public in 2008.

"The company is targeting to list on the Bahrain Bourse during the first half of 2014," the source said.

Few details relating to the IPO have been made public, although Zain's chief executive said in December his company wanted to keep majority control. Selling the IPO on a proportional basis would lead to Zain's stake dropping below 50 percent.

Gulf International Bank (GIB) became adviser on the IPO after Bahrain's Securities & Investment Co (SICO) left that role in June.

Bahrain's most recent major IPO - the sale of a 10 percent stake by Aluminium Bahrain in November 2010 - priced at the bottom of the indicated price range and the shares have since fallen by nearly half.

Zain Bahrain made a net profit of $14.3 million in 2013, down 15.7 percent from a year earlier. Revenue rose 5.5 percent to $213 million and its customer base increased 25 percent over the same period.

The company hopes a $100 million next-generation network upgrade, which began in 2013, will bolster income. - Reuters