The Israeli Web portal Walla Communications Ltd. announced on Monday that it has signed a strategic cooperation agreement with Yahoo! Inc. on Internet search engines. The agreement will allow the companies to challenge Google Israel's three-year reign of the market and provide an alternative to advertisers in the targeted advertising market. As part of the agreement, Walla launched an independent search engine a year ago, at a cost of $1 million, to upgrade its search engine. Under details of the agreement, Walla will now be able to use Yahoo's search engine, giving Walla access to one of the world's largest on-line databases, including searches in Hebrew, English and other languages. The version has been adapted to Israeli users by Walla's development department. Advertising on the search engine will be conducted through the Walla Advantage system, a "pay-per-click" model launched in May 2007.