The casino and hotel, for client ReBlackpool, will stand at 152m - under half the size of Atkins' Dubai tower - as Blackpool looks to increase its tourist trade, which has been falling steadily over the last 20 years.
The building will be the UK's first regional casino, and, it is hoped, a catalyst for development and rejuvenation to Britain's ailing Victorian holiday resort.
Reg Haslam, director of development at ReBlackpool, said: 'We want to create a memorable and commercially successful development that will change people's perception of Britain's most famous seaside resort, giving the UK market a compelling new reason to visit Blackpool.'
The scheme will develop an 800-room hotel, a brand new 'winter promenade', restaurants, bars and a 3,000-seat auditorium and conference centre.
The proposed 8ha site, which is being priced at £350 million, is the home of one of Blackpool's oldest casinos, the Grosvenor.
Gensler's London principal Ian Mulcahey, said: 'We aim to meet Blackpool's regeneration ambitions by presenting a solution that captures the imagination of the local community and investors.'