The Zankor Syndicate was a Mazarite led criminal syndicate. In 2164 the syndicate was led by Eldi Zankor.
Prior to 2164 the Zankor Syndicate lost much in the way of personnel and assets when the Mazarite government cracked down on organized crime. With the formation of the United Federation of Planets, Eldi Zankor allied her organization with the Orion Syndicate as the introduction of Federation law and order would further hamper the Zankor Syndicate.
As the Planetarist movement arose in response to the formation of the Federation, Zankor's organization infiltrated the movement, co-opting the grassroots activists and using the movement to further the organization's criminal aims. Two members of the syndicate infiltrated the campaign team of Planetarist Presidential candidate Anlenthoris ch'Vhendreni and diverted him to Babel in order to stage a clumsy assassination attempt on the man. Under further investigations the Zankor infiltration was discovered and ch'Vhendreni withdrew from the race after reevaluating his positions.
Knowing that the Federation would trace the staged assassination attempt back to the Zankor Syndicate, the Three Sisters had Eldi Zankor killed in order to ensure that the trail did not continue from the Zankor Syndicate back to the Orion Syndicate. While that was done it also had the effect of denying the Orion Syndicate access to Zankor Syndicate personnel and assets. (ENT - Rise of the Federation novel: Tower of Babel)