With reference to the method you recommend, it is much regret to inform you that it doesn't work well with it. In this connection we would appreciate if you could consider the above-mentioned suggestion. Your best attention would be highly appreciated.
ビジネスレターの返信としてオフィシャルに表現してみました。
With reference to the method you recommend, it is much regret to inform you that it doesn't work well with it. In this connection we would appreciate if you could consider the above-mentioned suggestion. Your best attention would be highly appreciated.
御社が提示された方法に関してのご連絡ですが、残念ながら上手くいかないことをご報告させていただいております。よって、この件に関しましては上記に述べております当社提案をご検討いただきたければ幸いと存じます。よろしくお願いいたします。
"Would it be acceptable to proceed with the method above?"
**"Would it be acceptable to proceed with the method above?"**
**"Would you be able to agree to the approach I proposed above?"**
ここでは **"Would it be acceptable to..."**（〜してもよろしいでしょうか）や **"Would you be able to agree to..."**（〜に同意いただけますでしょうか）を使うと適切です。
この文脈では「上記の方法」＝ **"the method above"**, **"the approach I proposed above"** などで表現できます。
日本 
アメリカ合衆国 
