letter of comfort　

letter of comfort　1.对某人取得贷款给予支持的信函；2.公司寄给银行表明子公司在可预见的未来将持续经营的信函　

1.a letter supporting someone who is trying to get a loan.2.a letter from a company to a bank stating that a subsidiary company（which has applied to the bank for a loan）will continue to trade for the foreseeable future.