John, the GDS represent only 5% of total common shares so I do not believe the delisting of GDS should affect the shareprice of PetroRio.
A GDS holder may either instruct Deutsche Bank to convert its shares into common shares traded in Brazil (prio3):
"Deutsche Bank will, upon request from GDS holders, deliver the underlying Common Shares to such holders of GDS in accordance with the terms and conditions of the Deposit Agreement and such GDS holders' written instructions."
or Deutsche Bank will sell the GDS holder's shares in Brazil:
"In the absence of written instructions from the GDS holders or their agents by the end of such four month period as to how the underlying Common Shares are to be delivered to a valid brokerage account, such Common Shares to which the former GDS holder was entitled will be sold in the market by Deutsche Bank and the net proceeds remitted to the former GDS holder."