Saudi billionaire Prince Alwaleed bin Talal and his investment company said Monday they are investing a combined $300 million into Twitter, giving the microblogging site a cash boost as it looks to entice more users and paying advertisers. The joint investment with Alwaleed's Kingdom Holding Co. follows months of negotiations and represents a "strategic stake" in Twitter, according to the Riyadh, Saudi Arabia-based investment firm. It wasn't clear how much of Twitter the prince will control.

Alwaleed, a nephew of the Saudi king, ranks 26th on Forbes' list of the world's richest people. He has a history of investing in media and technology companies, and said the deal represents an interest "in promising, high-growth businesses with a global impact." Twitter allows users to send short messages of up to 140 characters. The 5-year-old site has been instrumental in connecting protesters and relaying on-the-ground developments during this year's Arab Spring uprisings. Globally, the San Francisco-based company has more than 100 million active users who post an average of 250 million messages, or "tweets," a day.

Alwaleed is the main shareholder in KHC, which has a major stake in Citigroup Inc. The investment company also holds stakes in other Western giants, including Apple Inc. and Rupert Murdoch's News Corp. Alwaleed's decision to buy into Twitter likely goes beyond his interest in media and technology. Said Hirsh, a Mideast economist with Capital Economics in London, said Arab investors such as Alwaleed have long targeted trophy assets and well established brands.

"It is ... an investment into a well recognized brand with future growth potential," Hirsh said. In February 2010, Alwaleed's Rotana Group media company agreed to sell a stake of just over 9 percent to News Corp. for $70 million. Alwaleed is in the process of launching a new Arabic news channel that will challenge established players such as Qatar's Al-Jazeera and Saudi-funded Al-Arabiya. Twitter recently began rolling out a series of tweaks designed to make the site easier to navigate. The redesign also aims to allow for more detailed information about corporate brands as Twitter tries to convert more companies into advertisers.

The company earlier this year raised $400 million from venture capitalists and other investors. 

Twitter CEO Dick Costolo said in September that cash cushion would allow the company to control its own destiny — and for now avoid selling its stock through an initial public offering. By limiting its shareholders to a small group of private investors, Twitter doesn't have to disclose how much revenue it brings in. The research firm eMarketer estimates Twitter will generate close to $140 million in ad revenue this year and $260 million in 2012.