Yahoo! has entered into a definitive agreement to acquire an Arab online portal Maktoob.com, which claims to have more than 16.5 million users. Financial terms of the agreement were not disclosed. The transaction is expected to be completed in the fourth quarter of 2009.

Carol Bartz, chief executive officer of Yahoo!, said: This acquisition will accelerate Yahoo!’s strategy of expanding in high-growth emerging markets where we believe Yahoo! has unparalleled opportunity to become the destination of choice for consumers.

“Access to information and communications tools can positively impact people’s lives in many ways, and with the acquisition of Maktoob.com and our investment in the region, the Arab world will soon get a Yahoo! experience in Arabic with relevant local language content, programming and services.

While internet usage in the Middle East has grown more than tenfold since 2000, most markets are still in the early stages of adoption. According to the World Bank, while there are more than 320 million Arabic speakers worldwide, less than 1% of all online content is in Arabic, Yahoo! said.

The company said that the acquisition will extend Yahoo!’s current offerings by adding capabilities to deliver Arabic-language content and services, as well as Arabic versions of Yahoo! Messenger and Yahoo! Mail services. Maktoob.com is accessed by users in countries that include, UAE, Jordan, Kuwait, Egypt and Saudi Arabia.

Following the acquisition, Maktoob.com will become a wholly-owned subsidiary of Yahoo!. Ahmed Nassef, the current general manager of Maktoob.com, will continue to lead the Maktoob.com teams and will report to Keith Nilsson, senior vice president of Emerging Markets at Yahoo!.

Upon completion of the deal, the remaining Maktoob Group companies, including Souq.com, cashU.com, Araby.com, and Tahadi.com – will operate under a new entity called the Jabbar Internet Group, managed by Samih Toukan, founder of Maktoob.

Yahoo stated that going forward, it will have a strong commercial relationship with Jabbar Internet group and will include the promotion of Jabbar companies on the Maktoob.com portal.