MILAN, Oct 22 (Reuters) - Suitors for a stake in a

future venture combining Italian energy firm Sorgenia's assets

with those of solar power firm EF Solare are due to file their

binding bids by the end of October, two sources close to the

matter said.

The buyer would take a 27.6% stake in Sorgenia, held by

Spanish fund firm Asterion, to become a shareholder in a new

unified energy player with a stake of nearly 40%, which could be

valued at around 1 billion euros ($1.1 billion), one of the

sources said.

EF Solare and Sorgenia are both controlled by Italian

infrastructure fund F2i.

Greek energy and metal group Metlen, formerly

known as Mytilineos SA, is among suitors for the asset, the two

sources said. Investment group Sixth Street is also in the race,

one of the sources added.

The deadline for the binding bids has been postponed by one

month from an initial timing indicated at the end of September,

the two sources said.

Metlen and Sixth Street declined to comment. Asterion did

not immediately respond to a request for comment.

Sorgenia focuses on wind and biomass energy, with a total

installed capacity of 400 megawatts (MW), according to its

website. It plans to add some 200 MW in solar capacity through

2027.

EF Solare has 309 solar farms in Italy and 10 in Spain, for

a total installed capacity of 1071 MW.

Solar farms are the main drivers to add renewable capacity

in Italy as the country strives to meet Europe-wide goals to

decarbonise the economy.

Last year Italy added nearly 6 gigawatts (GW) in renewable

energy installed capacity, mainly thanks to solar projects.

($1 = 0.9234 euros)