Bayern Munich is preparing to sell a 5% stake to a family with a fortune in the heating equipment industry, in a deal that values the historic German club at €4 billion.

Following the capital increase, Viessmann Generations Group will increase its stake to approximately 6.7% in the German champions.

The deal was announced on Thursday, but the parties did not disclose the financial terms of the transaction.

However, sources familiar with the matter told Bloomberg that the deal values Bayern Munich at around €4 billion ($4.5 billion).

Although this would rank among the highest valuations in world football, Bayern’s valuation remains competitive with those of Europe’s biggest clubs.

In August, Fenway Sports Group sold a minority stake in Liverpool to a group led by Amazon co-founder Jeff Bezos, valuing the English club at $6 billion.

According to Sportico data, Real Madrid is valued at $7.7 billion, while Barcelona and Manchester United are each worth around $6.5 billion.

“This step strengthens the ownership structure of FC Bayern München AG. A further substantial reinforcement of our capital base also gives us greater flexibility at a time of constant change,” said Herbert Hainer, president of FC Bayern München eV and chairman of the supervisory board of FC Bayern München AG.

“As a fourth-generation family business, we want to contribute capital and our business expertise to this partnership. We want to play our part in maintaining a strong FC Bayern – a club with its own identity, economic independence and consistent success. Today marks the beginning of a partnership for generations,” said Max Viessmann, CEO of Viessmann Generations Group.

Bayern Munich will retain 70% of the club, while the remaining 30% will be held by four minority shareholders.