商务英语（英译中）,急求地道说法

商务英语（英译中）,急求地道说法
（某银行）hereby issue in favour of （某公司） an irrevocable Performance Bond for the sum of XXX as security for the fulfilment of the obligations of the Supplier regarding Purchase Order No._______,dated _________,amounting to a value of ___________,* and undertake to pay to the Buyer,at our counters,any sum within the above-mentioned limit upon the Buyer’s first written demand or tested telex issued by the Buyer’s bank specifying the reason for the Buyer’s claim,notwithstanding any objections which may be raised by either Party.
大意能看懂,但是从“and undertake”开始就不会落笔翻译了.求求各位精英帮帮忙了.会追分!