May 25 (Reuters) - Sweden's indebted SBB on

Saturday entered into a joint venture, SBB Social Facilities,

with U.S. based Castlelake and supported by Atlas SP Partners,

signing a loan agreement for approximately 5.7 billion Swedish

crowns ($534.36 million).

SBB Social Facilities will use loan proceeds to acquire

properties from SBB, to refinance debt to SBB and for certain

external debt, according to the statement.

($1 = 10.6669 Swedish crowns)