Google, which left China in 2010, could have had access to billions in additional revenue if not for the ban. Reuters

Google’s search-ad revenues are eroding on a global scale in large part because China, one of the world’s fastest-growing markets for information services, has banned the U.S. company’s offerings. Meanwhile, Baidu, which is based in China, is reaping the benefits, a new market survey shows.

The report, from research group eMarketer, estimates Google’s share of 2015’s $81.59 billion search ad market at 54.5 percent, down from 54.7 percent in 2014 and 55.2 percent in 2013.

While still the largest player in search advertising, Google -- based in Mountain View, California -- is losing out on China’s $14.9 billion market, eMarketer said. Chinese spending on search ads is expected to grow by 32.8 percent from 2014 to 2015.

Baidu is predicted to reach second place in search-ad revenue worldwide in 2015, followed by Microsoft’s Bing and Yahoo’s combined share of 6.5 percent. In fifth place is Sohu, another Chinese Internet company, which eMarketer predicted will grow at 61.6 percent in 2015, far outpacing any other search engine.

As spending on search advertising increases, eMarketer estimates that the market will reach $130.58 billion worldwide by 2019, up from 81.59 billion 2015, at 10 percent compounded growth. This global rise will further support China’s market growth and strengthen Baidu and Sohu.