Please bear with me .....3 Companies involved: A, B & C- Company's A & & are both in industries I'm interested in, but the roles aren't exactly what I'm after (over time the role will become interesting).- Company C operates in an industry I'm not only mildly interested in, but don't hate. However, the role is exactly what I'd like to be doing.Going through a recruiter, I've been able to secure a job offer with company A. Immediately prior to the offer, I was able to secure another offer with company B. The package that company B offered was higher than what was on offer at company A (base & bonus %).The offer company A made was exactly what I'm on now, however, after a bit of negotiating, they matched the base of company B. I've rejected company B and informally accepted with company A (nothing has been signed).I'm now in the final stages of interviewing with company C and I'm fairly certain I'll receive an offer. The figures being banded about are much higher than even Company B's offer.Is there anyway I can get company A to increase their offer without looking like a jerk? Despite their new - higher - offer, they are still well within their salary bracket for this role (offer @ £70k, range between £68k - £78k). If company A could increase the offer, I'd accept in a heartbeat and not look back. As it stands, there's a potential £10k chasm between the offer from company A and C which is causing me to pause.Apologies for the narrative. Any advice would be welcome.