Blackstone Group solidified its growing investment presence in Spain, winning an auction Wednesday for around €6.5 billion of Spanish mortgages, according to a person with direct knowledge of the deal.

The mortgages were issued by Catalunya Banc, a prominent lender in the Catalonia region that the Spanish government nationalised in 2011 as growing loan losses threatened to sink the bank. Spain has spent €12 billion in European bailout funds to clean up the Barcelona-based lender.