By Carol Dean Of Dow Jones Newswires LONDON (Dow Jones)--BP PLC (BP) arranged a $5.25 billion standby credit facility with a group of banks in early June for general corporate purposes and to bolster its balance sheet for possible claims against the oil spill in the Gulf of Mexico, people familiar with the situation said Wednesday. A total of $5.25 billion of standby bank lines were recently arranged by the company with a one-year maturity, two of the people said. A third said that the facility was arranged on a bilateral basis and more banks are likely to join the financing. Among banks likely to have participated in the financing are HSBC, Citigroup, Royal Bank of Scotland and Societe Generale, the people said. BP said to investors during a conference call on June 4 that in addition to this facility the company has $5 billion of cash and $5.25 billion of undrawn committed bank lines. "The $5.25 billion standby credit provides the company with additional liquidity to meet future possible claims," said Richard Birrer, analyst at BNP Paribas. BP Monday said it had spent $1.6 billion on containment, cleanup and compensation operations in the Gulf of Mexico so far. "Latest esimates from the company are in the range of $3 billion to $6 billion," Fitch said in its note Tuesday concerning immediate clean-up and claim settlements. Fitch downgraded BP long-term debt six notches to just above junk level to BBB from AA Tuesday on fears that the U.S. government would force it to pay billions of dollars up front into an escrow account to pay spill cleanup and compensation. --By Carol Dean, Dow Jones Newswires; 44 20 7842 9306 carol.dean@dowjones.com (END) Dow Jones Newswires June 16, 2010 12:01 ET (16:01 GMT)