Prime Minister David Cameron has given his backing to a deal which would see £170 million of investment and 8,500 jobs created in seaside resorts and towns.
The Greater Brighton City Deal will mark the start of a long-term commitment to securing a vibrant local economy which will provide jobs, culture, education and housing to over 600,000 people, according to Brighton and Hove City Council.
It is expected the deal will drive growth, support ambition and improve job prospects, earnings and business opportunities across Brighton and Hove, Lewes, Mid Sussex, Adur and Worthing, turning it into one of the highest performing urban economies in the UK operating on an international stage, a council spokeswoman said.
The deal has been unveiled by the Deputy Prime Minister Nick Clegg and Minister for Cities Greg Clark, and will be signed in Brighton today by Mr Clark, council leaders and the local enterprise partnership.
The £170 million of investment consists of £6.7 million from central government, £9.8 million from the local public sector and at least £155 million of private investment.
The deal will give Brighton and Hove the chance to compete with other major tech clusters around the world by creating a digital exchange in the heart of the city, where companies collaborate to use combined buying power to get faster broadband at lower prices, the Deputy Prime Minister's office said.
It will also help flood defence work, regeneration and employment at sites in Shoreham, West Sussex, and Newhaven, East Sussex.
Mr Cameron said: "Today's City Deal is great for Brighton, growing and harnessing the digital and creative skills that the city is rightly renowned for.
"With more power and freedom to run the local economy in the way they see fit, local people will be able to make decisions that directly benefit Brighton's businesses.
"By supporting new and innovative businesses, Brighton's deal will help us secure the nation's recovery and deliver our long term economic plan."
Mr Clark added: "Brighton's tech cluster has grown from very little 10 years ago to having 1,500 businesses today.
"It's already making a huge impact on Brighton's economic performance, and this City Deal will help accelerate its growth by ensuring that it can provide the space and infrastructure for high-value creative-technological businesses to grow. It can help turn Brighton into one of the most prosperous cities in the UK."
Jason Kitcat, Brighton and Hove City Council leader, said the deal was an exciting journey which would allow more power and responsibility within the city region.