To understand the gambling scene in Macau it is helpful to have a historical background. Gambling was legalized in Macau in the 1850's. In 1962 Stanley Ho gained a monopoly on gambling in Macau through his company STDM, Sociedade de Turismo e Diverses de Macau, or in English, Macau Tourism and Amusement Company. The sub-company of STDM that manages the casinos is SJM, Sociedade de Jogos de Macau, or the gaming company of Macau. In 2002 Stanley Ho's monopoly ended and the government of Macau sold off two new gaming licenses. With a gaming license, the holder can build as many casinos as he likes. The bidding was heavy, and in the end the winners were Steve Wynn and the a Hong Kong construction company, which renamed itself the Galaxy Entertainment Group.
The next part of the story I don't completely understand, but for some reason Galaxy was allowed a sub-license, which was awarded to the Sands, the U.S. gaming company that owns the Venetian. The reason for this has something to do with the Galaxy being partially owned by a Taiwaneese group, and the Hong Kong and Taiwan factions of the company could not get along. SJM and Wynn complained this split was unfair to them, because now they had an extra competitor. So, to be fair, the Macau gaming authorities awarded a sub-license to SJM and Wynn as well. The SJM sub-license was given to a partnership between MGM-Mirage and Pansey Ho, the daughter of Stanley Ho. The Wynn sub-license was awarded to Melco, an Australian gaming company. So there you have the six gaming companies of Macau. Every casino in Macau will fall under one of them.
Go to Gambling Basics.