* Kodmani says too many in SNC pushing partisan agenda
* Calls for new political authority, include Free Syrian Army
* Kodmani to focus on humanitarian efforts (Adds U.S. comment)
By John Irish
UNITED NATIONS, Aug 29 (Reuters) - Basma Kodmani, a prominent figure in the Syrian National Council who resigned on Tuesday, said the umbrella opposition group had become too focused on personal agendas and needed to be replaced by a new political authority.
Speaking to Reuters on Wednesday, Kodmani said the SNC was not doing enough to back the increasingly militarized 17-month revolt against Syrian President Bashar al-Assad.
"While the political role of the SNC is important, the credibility and legitimacy of a coalition of an opposition is related to its effectiveness," she said.
"My sense was that the SNC was not up to facing the increasing challenges on the ground and was not up to the performance I would have liked it to be," she said in a telephone interview from Paris.
Kodmani, one of the few women in the SNC, headed up the group's foreign affairs bureau.
With fighting reaching the capital Damascus and commercial center Aleppo, Western countries are increasingly anxious for the disparate opposition factions to agree on a credible plan for a transitional government to succeed Assad.
The SNC was formed in Istanbul last year as an umbrella organization to guide a democratic transition if Assad fell but has been accused by some of being dominated by Islamists.
"The groups inside the council did not all behave as one in promoting one national project," Kodmani said. "Some have given too much attention to their own partisan agendas, some to their personal agendas sometimes. That resulted in a major weakness in connecting closely with the groups on the ground and providing the needed support in all forms."
Another former SNC member, Randa Kassis, said on Aug. 23 she had been driven out of the group after expressing fear about Islamist domination.
"I joined the council to support a revolution and not play partisan politics," Kodmani said.
The Paris-based academic said the SNC had served its purpose, but that a new political authority that included the Free Syrian Army (FSA) had to be created.
France has said that it would recognize an inclusive provisional government if it managed to represent and gather the various ethnic and sectarian strands in the country.
"I am not talking about arming or financing, but coordination in the sense that the political and military authorities on the ground need to coordinate," Kodmani said.
"I think the FSA is willing to be under the control of a political authority, and my view is that we did not do enough to make this happen."
Kodmani said she would now work with people on the ground, institutions and projects that make more of a direct contribution to the current situation and the future of Syria.
Her efforts would also focus on getting humanitarian aid into the country and building trust between local channels and countries outside Syria that were often skeptical of local groups.
The U.S. State Department said it believed that Kodmani -- who has met Secretary of State Hillary Clinton several times -- would continue to work for Syria's future despite her decision to leave the SNC, and it downplayed the centrality of the SNC.
"We've said from the beginning that we see them as a legitimate representative, but we never embraced them as the sole representative because Syrians themselves had a number of other groups," State Department spokeswoman Victoria Nuland said.
"What's most important is not what group folks label themselves as being affiliated with, but that increasingly the opposition inside Syria and outside Syria are all talking about the same kind of democratic future." (Additional reporting by Andrew Quinn in Washington Editing by Vicki Allen, Cynthia Osterman and Eric Beech)