The Treasury is to invite applications this week for the role of FSA chairman.
The new chairman will succeed Sir Howard Davies who announced recently he is moving to head the London School of Economics.
A Treasury statement said: "We are looking for an individual of the highest calibre to lead the FSA in delivering a strong and effective financial services regulatory regime.
"As the single regulator for financial services in the UK, the FSA has one of the widest remits of any international financial services regulator.
"The scope of FSA regulation will increase further when the FSA takes on responsibility for conduct of business regulation for mortgages and general insurance in 2004/5. In light of this, it has been decided that the chairman should be supported by a separate chief executive."