The maximum amount of 1 billion euros ($1.1 billion) could be increased to 2 billion euros in the event of large demand, Eni said of its return to bond issuance for small investors after an absence of more than a decade from this market.

The bond, which Eni said in a statement will have a five-year maturity and pay a fixed rate of not less than 4.3%, taps into a greater appetite for debt linked to meeting energy transition targets.

"The bond will enable Eni to pre-fund potential future financial needs, to maintain a well-balanced financial structure and to further diversify financial sources," it said.

The last coupon payable on Feb. 10, 2028 will be linked to the achievement of sustainability targets related to the reduction of net greenhouse gas emissions and the increase of Eni's renewable capacity installed by 2025.

If one of the targets is not hit, the interest rate related to the coupon payable at maturity will be increased by 0.50%.

Investors will be able to subscribe online and the debt will be listed on the bond market managed by Milan stock exchange.

($1 = 0.9310 euros)

(Reporting by Francesca Landini; Editing by Alexander Smith)