Investec will continue to back the Derby Festival until 2021 after agreeing a 10-year extension to their current deal with Epsom.
The firm began sponsoring the two-day meeting, which features the Derby, Oaks and Coronation Cup as its headline events, in 2009 and they still have a year to run on their existing contract.
However, Investec and Epsom have now sealed a deal which represents the biggest sponsorship agreement in British racing history.
The extension will see the Investec Derby reinstated as the richest race in the UK offering a prize fund of £1,325,000 in 2012 with significant boosts for the Oaks and Coronation Cup prizes already announced last month.
Epsom's managing director Rupert Trevelyan said: "We are delighted that Investec have agreed to extend their sponsorship for a further 10 years.
"They are a fantastic brand to work with, very forward thinking and proactive, and we will continue to work in collaboration with them to develop the Investec Derby Festival.
"It is only fitting for such a prestigious event like the Derby to have such a high profile, committed and long-term partner."
The new agreement will also see Investec continue its sponsorship of the Spring Meeting with Epsom's season opener being six weeks out from the two-day Festival.
