Acciona said late on Wednesday that Citi, JP Morgan, Goldman Sachs, Morgan Stanley and Bestinver Securities have been asked to organise the listing, confirming an earlier Reuters report.
"The perimeter of the new company will include Acciona's entire energy business, excluding its stake in wind turbine manufacturer Nordex," Acciona said.
The company said it would retain a 70% stake and free float would be at least 25% after the listing. But Acciona added that the size and structure of the placement had not yet been decided.
Shareholders gave their blessing on Monday to Acciona's plan to spin off the renewable energy generation and supply business, which brings in most of its money, and sell at least a 25% stake in it.
Renewable energy has become an increasingly popular sector for investors worldwide as governments and corporations try to wean themselves off fossil fuels and stem climate change.
With wind farms in the United States, Australia, Spain, Chile and Mexico, Acciona plans to plough proceeds from the sale into nearly doubling generation capacity to 20 gigawatts (GW) by 2025. It will also use the money to pay down debt.
Chief Executive Jose Manuel Entrecanales, whose family controls around 55% of the parent company, has said he wanted to do the deal in the first half of this year.
Entrecanales has declined to say how much money Acciona hopes to raise, but two people familiar with the matter said it was looking for a valuation of 10 times the unit's 2020 core earnings of 831 million euros.
A third person familiar with the matter said the deal could value the business at more than 10 billion euros.
Fellow energy groups Repsol and Eni are also considering partial listings of their low-carbon energy businesses to help finance transitions from oil and gas.
On Acciona's energy IPO, STJ Advisors and AZ Capital will act as independent advisers, while law firms Uría y Menéndez and Davis Polk & Wardwell are acting as issuer's legal advisers. Linklaters will act as counsel to the banking syndicate.
($1 = 0.8358 euros)
(Reporting by Arno Schuetze, Abhinav Ramnarayan and Isla Binnie. Editing by Mark Potter and Cynthia Osterman)
By Abhinav Ramnarayan, Arno Schuetze and Isla Binnie