Comma or Hyphen? Please advise.

Hi,

Which sentence is grammatically correct?  Do I have a comma or hyphen after the corporation name? Or do I write it a different way?  Thanks for your help.

The corporation you work for - Mantel, is manufacturing a secret drug called Nectar and giving it to its soldiers.

The corporation you work for - Mantel - is manufacturing a secret drug called Nectar and giving it to its soldiers.

The corporation you work for, Mantel, is manufacturing a secret drug called Nectar and giving it to its soldiers. Needs the second comma

The corporation you work for - Mantel - is manufacturing a secret drug called Nectar and giving it to its soldiers. OK

Clive

 

Hi Grammar Geek,

I asked the same question as you did, and found this introduction to a computer game called Haze:

"Twenty-five years in the future. Governments have outsourced military operations to private multinational corporations. As Jake Carpenter, a newly enlisted soldier in the Mantel army, you are seeking fulfillment and thrills by fighting for a good cause.

Thanks to their high-tech arsenal of vehicles, deadly weaponry, and performance enhancing bio-medical support, the Mantel Corporation's ruthlessly efficient soldiers are the most feared by terrorists, dictators, and the corporation's political enemies."

Hoa Thai