(Reuters) - A donor for New York City Comptroller John Liu was indicted on federal conspiracy and wire fraud charges for evading campaign finance rules on Wednesday, dealing another blow to the Democrat's bid to succeed Mayor Michael Bloomberg.

Preet Bharara, U.S. Attorney for the Southern District in New York, said in a statement that the fund raiser, Xing Wu Pan, used "straw donors" to funnel cash to an unnamed candidate.

Liu has previously confirmed the donor was one of his supporters.

Neither a spokesman for Liu, who is scheduled to give a State of the City address on Thursday, nor his lawyer were immediately available for comment.

Liu's speech will be the first such address in recent memory by a city comptroller as such speeches are usually reserved for mayors.

Liu, who was born in Taiwan, has tapped the Chinese-American community in New York City for campaign donors. One of those donors, Pan, who also is known as Oliver Pan, illegally raised $16,000 for a candidate in a 2013 citywide race, the U.S. attorney previously said in a complaint.

The next mayoral race will be held in 2013.

Pan's $16,000 contribution exceeded the amount individuals are allowed to contribute, which is the basis for the fraud charges, federal officials have said. The scheme also illegally boosted the amount of matching funds that Liu qualified for, they said.

(Reporting By Joan Gralla, Editing by G Crosse)