By Antoni Slodkowski

UNITED NATIONS, Oct 30 (Reuters) - An informal poll by the United Nations Security Council on Friday showed former Costa Rican Vice President Rebeca Grynspan extended her lead as frontrunner in the race to become the 10th UN secretary-general, two people close ‌to the process said.

Grynspan got 11 votes in favor and 4 against on the 15-member council, marking her strongest showing in seven closed-door ballots conducted in recent months to replace Antonio Guterres as he finishes his second five-year term this year.

Whoever wins will have to tackle multiple crises, including several wars, cutbacks in American contributions to the ​UN, and the 193-member body's declining political relevance as Washington has pulled out of dozens of its agencies.

Securing the council's recommendation requires at least 9 positive votes and no "discourage" votes from the five permanent ​members - France, Britain, the US, Russia and China. Friday's ballot was not coded in a way that would allow decyphering of how the "P5" voted.

Friday also marked the first poll since United Arab Emirates diplomat Lana Nusseibeh entered the race, but the Middle Eastern contender and former ambassador to the UN received 7 votes in favor, 6 against and 2 marked as "no opinion."

(Reporting by Antoni Slodkowski)