I had always dreamt of working with a company like yours. Thank you very much for sending me an offer letter. It would ne great to work with your company starting from ___________.
But during last week I happened to attend another interview with a different equally competent company as your and they are offering me a salary of ______________ per months which is 25 % higher than the salary you offered.
Before accepting your offer I thought of informing you regarding the market trend. I would like to mutually negotiate and settle down with a more appropriate salary.
I am eagerly waiting for your reply.