By Marc Jones LONDON (Reuters) - Rating agency Moody's said that Greece's rock-bottom credit rating was unlikely to be raised any time soon, despite Greece agreeing terms on Monday for a third euro zone bailout. Colin Ellis, the firm's chief European credit officer, said the immediate focus was on whether the Greek parliament approved the proposed deal on Wednesday, and on whether financing could be found to meet a 3.5 billion euro payment to the European Central Bank next Monday. "The balance of risk is still heavily skewed in one direction." Greece is currently rated Caa3 by Moody's after a downgrade at the start of the month.