H1B and OPT confusions

[cherisha]

I have got employed by co. A who sponsored for my H1B which has got approved. However I still have my OPT which jsut started this June. I am wondering if my OPT will still be valid after Oct 1st ?
Since I do not want to work with co. A and intend to switch jobs can I do so on the basis of my OPT.
Is there a way to terminate the H1B or transfer it ?
I have not yet started work with co. A and do not have any pay stubs from them but since I am interested in joining co. B I wanted to switch positions.
Please advice.

[kabkaba]

If H1 was a COS case, your status will be H1 from October 1 and you will have to work for the petitioning employer.
A new employer may file a new cap-exempt petition any time before October 1 (or transfer petition after October 1) to employ you. You may work for that employer after their approval.

[cherisha]

Thanks for your response.
So now if I want to work with the new co. I can ask them to file for a transfer and once it gets approved I can work for them ?
Am I allowed to work on my OPT right now with the new co.

[kabkaba]

If you are on OPT you can work for new company.
New company can file new petition now. If the petition is approved before October 1, you can continue to work for them. If petition is not approved/filed, then you will have to work for old employer until it gets approved.