A Google sign is seen during the WAIC (World Artificial Intelligence Conference) in Shanghai, China, September 17, 2018. REUTERS/Aly Song

(Reuters) - Alphabet Inc's GOOGL.O Google said on Tuesday it would allow certain regulated cryptocurrency exchanges to advertise in the United States and Japan, easing an earlier ban on all cryptocurrency ads.

The changes will take place in October and advertisers will need to be certified with Google for the country where the ads will appear, the search engine giant said in a blog here post.

The company said in March it would ban advertisements for cryptocurrencies and initial coin offerings, starting June.

Google's action follows a similar move by Facebook Inc FB.O. The social media giant has allowed certain ads promoting cryptocurrency and related content from pre-approved advertisers, while banning those tied to binary options and initial coin offerings.

Google's move to ban such ads in March had sent the price of the best-known cryptocurrency, bitcoin BTC=BTSP, down more than 10 percent.