Plans for a new industry leader in Thailand, with a market share of more than 50% of mobile subscribers, have been held up over competition concerns since they were announced in November.Conditions imposed last week by the National Broadcasting and Telecommunication Commission (NBTC) include a price ceiling and price controls as well as independent verification of cost structures and service fees for at least five years.

Telenor, however, is seeking more information on what that would entail, its chief executive Sigve Brekke told Reuters.

Asked whether the deal was at risk, Brekke said Telenor was now "engaging in a dialogue with the regulator to better understand the conditions and what they entail."

While the NBTC cannot outright reject or approve a deal, it can stipulate demands that Telenor needs to comply with if it chooses to complete the merger, Brekke said.

"We need now to understand what these conditions really mean... it is hard to understand," he said.

"One thing is a tariff structure they want us to have, and also... as a service provider, how they can use our network - those things are among what is unclear," he added.

Telenor, which has about 175 million customers in eight countries across the Nordic region and in Asia, and CP Group are slated to hold a third of the shares each in the new entity, which would overtake Advanced Info Service (AIS) as market leader in the south-Asian country.

True and DTAC have 34% and 21% of mobile subscribers, respectively, while AIS controls 44% of the Thai market.

(Reporting by Victoria Klesty, editing by Terje Solsvik and Alexander Smith)