I have a job offer from company A and I mentioned that during hr rounds to another company B. Now company B has selected me but before sending the offer letter to me they want the offer letter of company A. I don't know what to do now. Will I send the offer letter from A to B or not? If I send it will the company B tell A that I have been looking for job in company B? If I don't send them the offer letter can B deny me the job ? I don't want chance from B to let go but at the same time don't want to end up losing both the chances. Can anybody give me any suggestion? Thank you in advance.
Worst case scenario, this is what happens when you forward the letter. Best case scenario, you still weaken your negotiating position if you forward it (as Kilisi mentioned).
Basically, there is little that's good that can come out of forwarding such a letter. Personally, this is what I would write to company B instead:
"I'm sorry, but I can not in good conscience forward a private communication sent to me from another potential employer."
Please note the purposefully vague language I'm using here. It's important to not even disclose the name of company A (unless you already did). If they ask, just tell them what the company does in the most general terms, so that they know the kind of company that they're up against, but you certainly don't need to be specific.
Or if you already told them that you'd forward the offer letter to them, you could simply say:
"I'm sorry, but I changed my mind. I know what I said earlier, but I can not in good conscience forward you a private communication sent to me from another potential employer."
And yes, it's company B's prerogative to decide whether you should become their employee or not, so they could very well deny you the job on the grounds that you didn't forward that offer letter to them (which is well within their rights). But at some point, you have to respect yourself enough and be willing to walk away.
After all, if a competing candidate requested a copy (or a partial screenshot) of the resume of the leading candidate for that same position, or if a candidate requested that the employer forward him a copy of the counteroffer made by another candidate. That would equally be a non-starter.
And what happens if company B doesn't believe that you have an actual offer on the table from another company since you're unwilling to show an offer letter? That's fine. If they don't believe you, that's on them. And it's not your obligation to justify or explain yourself further, and it's your prerogative to be able to walk away from any potential employer, especially any potential employer that makes unreasonable requests.
I can think of two reasons why they'd ask:
(a) They think you're lying about having another offer, or about the amount or some other details of the offer.
(b) They want to know what kind of salaries other companies are offering, or gain some other information about the competition.
Either way, asking for a copy of the other company's offer letter seems a little ... tacky, inappropriate, bad form ... to me. I'd reply something to the effect of, "I don't think it's appropriate for me to forward private correspondence from another company." That's the sort of thing I'd rather say in an email than in person, but if I had to do it in person, I'd try to look and sound confused, like, "why in the world are you asking me this?"
If they push on this, I would consider that a reason not to want to work for B.
If you already have an offer from A, presumably you are not desperate to get an offer from B, so you don't have to give in to unreasonable demands. Well, I don't know how good the offer from A is or what you expect from B. As always in real life, sometimes you have to weigh the pros and cons.
Your mistake was mentioning the other offer. They expect that every candidate is interviewing at multiple companies. But you mentioned the other offer so now the face a dilemma.
They were prepared to offer you X but you have an offer in your hand. They know that the most they can offer is X+delta. They want to know if they will win with X so they don't have to offer x+delta. They don't want to waste any more time if x+delta will be too low. Showing them the offer letter will cut right to the end. They will either just beat A's offer or they will walk away.
of course if you told them how much A is offering while you were talking to HR, they want to see the letter before they push for a funding decision from the company. They don't want to maximize their offer when there was no offer.
You have to decide which you want to go with. Take the written offer from A, or pursue a potentially better offer from B. Keep in mind your opinion of B's HR is not very good right now.