By Matt Smith

DUBAI (Reuters) - Twitter Inc launched advertising services in the Middle East and North Africa on Sunday as the social media firm seeks to exploit a tripling of its regional subscriber base following its widespread use during the Arab Spring protests.

Digital advertising is relatively undeveloped in the region, accounting for an estimated 4 percent of its total advertising spending, but a young, tech-savvy population and rising Internet penetration points to significant potential for growth.

"The two are interconnected - the rapid growth of our user base with the timing of why we want to help brands connect with that audience," said Shailesh Rao, Twitter vice-president for international operations.

Twitter does not provide a regional breakdown of its more than 200 million users worldwide, but Rao said its MENA subscriber base had tripled in the past 12 months.

The company has recruited Egypt's Connect Ads, which is ultimately owned by Cairo-listed Orascom Telecom Media and Technology, to launch advertising initially in Egypt, Saudi Arabia, Pakistan, Kuwait and the United Arab Emirates.

Pepsi and Saudi telecom operator Etihad Etisalat (Mobily) are among its confirmed clients, the company said.

Twitter says the products it promotes typically have an audience response rate of 1 to 3 percent, significantly higher than traditional advertising rate of 0.1 to 0.5 percent.

"Social media advertising is totally different because it relies on what people say. It's about two-way, not one-way, communication," said Mohamed El Mehairy, Connect Ads managing director.

(editing by Jane Baird)