H1B - Change of Employer

[xaanaadoo]

I am in my 10th year of H1B. I have a approved I140 from my current employer (Employer A). I am thinking of changing my job (Employer B). Can I apply for a new H1B through employer B without applying for a new labor and I140 (assuming my current employer doesn't revoke the approved I140? Will I get 3 years on my new H1B is the above scenario is possible? Anything to watch out for?

Thanks.