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.
How long does it takes to transfer the Visa to new Employer B.

[kabkaba]

Yes, B can file a cap-exempt petition for you at any time. After it is approved, you can travel to US with the new petition and the existing Visa in your passport. For H4 there is nothing to 'transfer', your dependents can travel with you (or after you) using your new petition and the existing Visas in their passports.

[deep3by4]

Thanks a lot for the response.
Normally approximately how many days does it take to get the Petetion approval by employer B for the H1-B Visa transfer.

[kabkaba]

Same as any other. 2 to 3 months for regular, 15 days for premium.