Very recently I get to know that Systems (Pvt.) Ltd. is also sponsoring H-1B Visas. They have offices in Karachi and Lahore:
Head Office
Chamber of Commerce Building, 11 Sharae Aiwane Tijarat, Lahore, Pakistan
Karachi Office
E-5, Central Commercial Area, Shaheed-e-Millat Road, Karachi, Pakistan
The information that I got is that they have sponsored quite a lot of candidates in recent years and in fact laud themselves as being the front runner in H-1B sponsorships as far as the counts are concern.
Their US front is Visionet Systems - http://www.visionetsystems.com
So, I’ve updated the original post and if you guys have information of other companies in Pakistan who are sponsoring H-1Bs, please let me know. Drop me an email or a comment on any of these posts and I’ll update the relevant posts. Thanks!