FILE PHOTO: A man walks up stairs at the eurozone's largest bank Santander's headquarters in Boadilla del Monte, near Madrid, Spain March 16, 2016. REUTERS/Juan Medina/File Photo

MADRID (Reuters) - U.S. investors Blackstone and Centerbridge are considering a 3 billion-euro ($3.5 billion) offer for Banco Santander’s headquarters in Madrid, two sources with knowledge of the matter said on Wednesday.

“Blackstone is in talks with Centerbridge about a joint offer for 3 billion euros and it looks like the bid will be submitted next week,” one of the sources said.

The potential offer was also reported on Wednesday by Bloomberg and earlier this week by Spanish website el confidencial.

Blackstone, Centerbridge and Banco Santander declined to comment.

A deal would extend Blackstone’s presence in Spain, which is enjoying an economic rebound. The U.S. investor bought control of property worth 10 billion euros from Santander in August last year.

Santander’s headquarters, which houses around 6,500 employees, is owned by Marme Inversiones, which in 2008 bought and leased back the property to Santander in a 40-year deal for 1.9 billion euros.

Marme sought protection from creditors in 2014 after failing to pay the 1.56 billion euro senior loan it took out to purchase the property, according to Bloomberg.

A Spanish court in charge of liquidating Marme’s assets announced in July that investors would be able to submit offers for Santander’s headquarters to the court.