Queensland Premier Annastacia Palaszczuk said the Echo bid was the stand-out because of the better use of public space and because the consortium was ready to start straight away.
"This development will transform Brisbane's CBD. Construction means thousands of jobs. Some 3000 during construction and 8000 ongoing jobs," Ms Palaszczuk said on Monday after cabinet signed off on the bid.
"We are very excited about this proposal and what it means for Brisbane – making it a premium tourist destination."
Echo is developing the project with Hong-Kong based business partners Chow Tai Fook and Far East Consortium. Collectively it is known as the Destination Brisbane consortium.
State Development Minister Anthony Lyneham said the Echo proposal won them over because it had more open space – room for about 26,000 people – and a greater variety of accommodation, with four, five and six-star hotels.
The trio plans to build a new casino, retail and entertainment complex on the banks of Brisbane River, next to Echo's dated Treasury Casino, opening in 2022.
Construction of the project is due to begin by late 2016.