May 25 (Reuters) - SBB said on Saturday it is forming a joint venture with U.S.-based private credit firm Castlelake, its second in about three months, which will help ease the Swedish real estate group's debt woes.

Under the deal, SBB and funds managed by Castlelake have signed a loan agreement of 5.7 billion Swedish crowns ($534.36 million). The joint venture will use the funds to acquire properties from SBB, refinance debt to the Swedish firm and also certain external debt, according to an SBB statement.

Atlas SP Partners will be part of the lenders, it said. The portfolio will be operated through a management agreement with SBB from which the properties are being acquired for 9.5 billion Swedish Crowns, the market value as of March 31, 2024, it added.

SBB and Castlelake signed a similar deal in February for another joint venture to receive a loan of 5.2 billion Swedish crowns.

SBB announced in March it is buying back its debt at a discount of 60% compared to their original value, in an attempt to calm investors' nerves as it scrambles to tackle a multi-billion debt pile.

The Swedish landlord predicted earlier this month that financing conditions would improve as it was making further write downs on the value of its properties. ($1 = 10.6669 Swedish crowns) (Reporting by Urvi Dugar in Bengaluru; Editing by Chris Reese and Muralikumar Anantharaman)