Working with Old H1b employer after transferring to current employer

[abhijeet.wankhede]

While working with my current employer, I got offer from another employer for US position by filling H1B petition, without leaving my current employer.
Here is the scenario,
- My current employer in India - "CURRENT A"
- External employer filed and stamped H1b VISA - "EXTERNAL X"
- While working with CURRENT A employer and without leaving CURRENT A,
I got offer from EXTERNAL X for US position by filling H1B petition.
- I got my H1b VISA stamped on 15th Jan 2015 with EXTERNAL X employer ( without leaving CURRENT A)
- Till May 2015 I wished not to travel to US because of my family dependency.
- In June 2015 my CURRENT A employer while working with them offered me US position with them.
And filled H1b petition in same month with premium processing
- On July 3rd, 2015 I got my petition approved with CURRENT A employer.
- But in between this petition process my CURRENT A employer unfortunately lost this US position and till date they do not have any position available with them for me.
So right now my current status is
1. I am still working with CURRENT A employer
2. I have my EXTERNAL X employer’s valid H1B petition and stamped visa.
3. I have valid H1b petition with my CURRENT A employer.
4. I have never travelled to US.
I am sure the EXTERNAL X employer have US position available with them.
Considering this, am I eligible to travel and work with EXTERNAL X employer on their valid H1b stamped visa?