Corp. Counsel, May 2010 at 25, mentions in passing that Mitchell Zamoff is the “co-general counsel of United-Health Group.” Before, I have wondered how twin GCs parcel out decision-making and avoid competition (See my post of June 16, 2007: co-general counsel at Citigroup and the former Computer Associates; and April 2, 2009 #1: Greg Palm at Goldman Sachs.). Other disadvantages of dual GCs would seem to be the double reporting burden on the CEO or some other executive, the challenge of maintaining compensation equity, and the complexities of allocating and delineating responsibilities.
The rare opposite, by the way, happens if two organizations share a general counsel (See my post of March 28, 2006: two universities, one general counsel.).