FRANKFURT/LONDON (Reuters) -State-owned Dutch power grid operator TenneT has kicked off talks with investors about the sale of a minority stake in its German division, four people familiar with the matter said, in what could become one of Europe's largest deals in 2025.

TenneT Germany has a regulated asset base (RAB), a key valuation gauge for energy grids, of 27.8 billion euros ($31 billion) as of 2024, which is set to grow by 25% each year through 2029, according to an investor presentation on its website.

A sale of new shares in TenneT Germany could raise up to 12 billion euros, three of the people said, adding that the amount could be significantly lower depending on the size of the stake settled upon and level of debt.

The Dutch state has committed to guarantee a BBB-rated capital structure for TenneT Germany, in line with other German high voltage grid operators (TSOs).

Non-binding bids for the business are due mid-June, the sources said, speaking on condition of anonymity because the matter is private.

TenneT and the Dutch government declined to comment.

The U.S. trade war has stymied dealmaking in recent weeks but grid assets, which are regulated and provide fixed returns, are expected to be more attractive to investors against a backdrop of falling interest rates and heightened economic uncertainty, the sources said.

Funds including Apollo Global Management, Canada's Caisse de depot et placement du Quebec (CDPQ) and Macquarie are interested in the sale, two of the people said.

BlackRock-owned Global Infrastructure Partners (GIP) and CPP Investment Board (CPPIB), which manages Canadians' pension savings, are also expected to show interest, one of the people and a third one said.

More suitors could emerge and parties are expected to team up given the potential size of the deal, two of the people said, adding there was no certainty of a transaction.

Apollo, CDPQ, Macquarie, GIP and CPPIB all declined to comment.

The Dutch government has embarked on a dual track process for TenneT Germany after a partial sale to German state lender KfW failed to materialise last year. The Hague remains open to Germany taking a stake in the company.

Apart from a sale, the government could opt for a partial initial public offering of the business.

Dutch Finance Minister Eelco Heinen, in a letter sent to parliament this week, said he wanted to settle on one of the two paths in early July.

"Based on discussions with investors and expected non-binding bids, I will assess with TenneT what is expected to be the best option," he said in the letter dated May 13.

With a network of more than 14,000 kilometres, TenneT Germany is the country's largest high-voltage power grid operator and made earnings before interest, tax, depreciation and amortisation of 2.2 billion euros in 2024.

($1 = 0.8919 euros)