UPDATE 2-Competition, regulation threaten high-flying Tencent

* Q3 net profit soars 93 pct as online gaming booms

* Opaque regulations pose challenges to rapid growth

* Shares end up 4.2 pct ahead of results; near triple in 2009 (Adds analysts quotes, details)

By Melanie Lee

SHANGHAI, Nov 11 (Reuters) - Tencent Holdings (0700.HK), China's most valuable Internet firm, faces challenges from regulation and competition to maintain its breakneck pace of growth after reporting a near doubling in third-quarter profits.

Tencent's growing dependence on online gaming puts it at risk of increasing regulation of the fast-growing industry by heavy-handed Chinese officials concerned about negative influence of games over issues such as violence and addiction.

NetEase (NTES.O), the country's No. 3 online game operator, recently spotlighted that risk when it got caught in a turf war between two government agencies, putting a promising new title at risk and causing its shares to drop. [ID:nN02450107]

Such developments could similarly affect online game makers, who are often dependent on one or two hit titles for big portions of their revenue from their Internet value-added services. Analysts already expect Tencent's profit and revenue growth to slow to around 40 percent next year, about half of this year's rate, according to Thomson Reuters I/B/E/S.

"If their mainstream revenue is still from the Internet value-added services, we don't think that kind of growth is sustainable in the coming three to five years," said Edward Yu, CEO of data tracking firm Analysys International.