July 30 (Reuters) - A first informal U.N. Security Council poll on Thursday showed former Costa Rican Vice President Rebeca Grynspan as the early front runner in the race to become the next secretary-general of the world body, followed by former Guyanese Foreign Minister Carolyn Rodrigues-Birkett, two diplomats told Reuters.
One diplomat said Argentina's Rafael Grossi, head of the U.N. nuclear watchdog, was in a "surprise" third place among the seven candidates for the post. In the non-binding voting by the 15 members of the Security Council, Grynspan received 10 "encourage" votes to nine for Rodrigues-Birkett and seven for Grossi.
(Reporting by David Brunnstrom and Michelle Nichols; Editing by Doina Chiacu)
