by your first class bank in our favour upon signing Sales Contract.
问题描述：
by your first class bank in our favour upon signing Sales Contract.
Shipment will be effected within 25 days after receipt of the relevant L/C issued by your first class bank in our favour upon signing Sales Contract.
这个句子中by your first class bank in our favour upon signing Sales Contract.
答
其实应该反过来翻译,说通俗一些就是兹凭已签定合同上的SELLER做为L/C的受益人,并由first class BANK(意思就是和出口商银行有往来业务联系的银行)开立此L/C