H1-Visa Transfer from Employer A to Employer B while outside US.

[deep3by4]

Am currently working with Employer A and have got my H1-B Petition done and Visa stamped. But I have still not entered US using the visa.

An Employer B in US would like to employ me.

Is it possible for my H1-Visa to be transferred to Employer B even while outside US.

Can the H4 dependent Visa also been transferred while transferring my H1-B.

If so, what are the steps to be followed for the same and what documents are required for processing the H1-B & H4 Visa transfer.

Please let me know how long does it takes to transfer the Visa to new Employer B i.e approximately how many days does it take to get the Petition approval by employer B for the H1-B Visa transfer.