The new institution will include mechanical, electrical and incorporated engineers and would dwarf the Institution of Civil Engineers' 80,000 strong membership.
All are agreed that such a strong membership base would significantly boost their ability to influence decision makers.
In a letter to IEE council members, president Professor Michael Sterling said: 'We do not think it would be sensible for each institution to respond to these trends by individually broadening its scope. A new body of this kind would be far more effective.'
An approach was then by made to IMechE.
The IEE is the largest of the UK's engineering institutions with 120,000 members. The IMechE has around 80,000 members and the IiE around 40,000.