Bids have been submitted for an unknown number of blocks, and some of the permits attracted multiple bids.
Executives say one hotly-contested area was Block 135, in water depths of between 200 and 1000 metres and bordering ConocoPhillips' blocks 133 and 134. There has been no official confirmation or public announcement of the round by PetroVietnam.
Nam Con Son contains producing fields such as the BP-operated Lan Tay and Lan Do gas fields and the South Korean-owned Rong Doi project.
