DUBAI, Jan 11 (Reuters) - Stockholm-listed investor Vostok New Ventures Ltd VNVsdb.ST has bought 10 percent of Dubai-based Propertyfinder Group for $20 million, valuing the online property portal at $200 million in one of the largest investments of its kind in the Gulf.

Propertyfinder will use the money to expand its sales and marketing operations in the Middle East and North Africa and invest in proprietary technology, the company said in a statement on Monday.

Bermuda-based investment firm Vostok has numerous investments in web-based companies, including stakes in Russian online classified platform Avito, Pakistani property portal zameen.com and Egyptian recruitment website wuzzuf.net, according to Vostok's website.

"Vostok brings a lot of expertise," Propertyfinder chief executive and founder Michael Lahyani told Reuters.

The investment comes despite a downturn in Dubai's real estate sector, Propertyfinder's home market. Sales prices showed double-digit percentage declines in the first 11 months of 2015, industry consultants CBRE estimated in December, forecasting further drops in 2016. ID:nL8N1432K5

"We're not seeing any significant slowdown at all, at least from a dealer perspective, in our traffic," said Propertyfinder's Lahyani. "As long as people are renting and buying and selling, the brokers and developers are in business and it's pretty good for us."

Real estate brokers and developers pay a monthly subscription to advertise on Propertyfinder, founded in the United Arab Emirates a decade ago. Since 2012 the portal has launched websites for Qatar, Saudi Arabia, Egypt, Morocco, Bahrain and Lebanon.

Lahyani said his firm attracts 1 million visits monthly, generating about 300,000 leads. The UAE accounts for more than half of Propertyfinder's revenue, with visits to its UAE website split 60-40 between rentals and sales.

"The other markets are growing much faster, they're catching up," said Lahyani.

Qatar is the company's second-largest market by revenue, but Lahyani said more populous Egypt and Saudi Arabia offered the most growth potential.

(Reporting by Matt Smith; Editing by Kenneth Maxwell) ((matt.smith1@thomsonreuters.com; 00971506354039; Reuters Messaging: matt.smith1.thomsonreuters.com@reuters.net))

Keywords: EMIRATES VOSTOK NEW VNTRS/PROPERTYFINDER