William Hill, Unibet and Betway have all seen their sites blacklisted by the Lithuanian Gaming Control Authority.
The authority has asked ISP providers in the country to block the sites after the National Parliament issued a list of blacklisted companies who are deemed to have broken Lithuanian online gambling laws.
The three sites are the first on the list to have been blocked.
Lithuania has passed new regulations on overseas companies offering online gambling within the country. At present only online sites TonyBet and Orakulas are allowed to offer online gambling within Lithuania as they have been fully licensed within the country.
