PROVIDENCE, R.I. - Republican mayoral candidate Daniel S. Harrop withdrew from the race to succeed Mayor David N. Cicilline on Thursday and will instead challenge state Rep. Edith Ajello after being appointed to fill a vacant ballot slot by state Republican Chairman Giovanni Cicione.

Harrop filed his declaration of candidacy for the mayor's race earlier this week after spending the last few months campaigning for the office, which he ran for in 2006. He was endorsed by the city Republican Committee on Monday as the only Republican candidate in the race.

State election law allows for the chairman of a state political party to appoint candidates to fill unchallenged seats for up to 24 hours after the close of the declaration period, according to an announcement from the Harrop campaign.

"We have been talking about this for a while now. I am happy with the wide range of candidates that have entered the race, giving the people of Providence a clear choice in November," Harrop said of the mayor's race. "This allows me to help the GOP by challenging a long time incumbent in the State House who needs to answer to the voters for the financial damage that she and her colleagues have done to our state."

Ajello, a deputy majority leader, has represented District 3, which covers the East Side of Providence, since being elected in 1992.

Harrop is a practicing psychiatrist in Providence, Chairman of the Board of Directors of the Ocean State Policy Research Institute, and Finance Chairman for the state Republican Party.

His decision to drop out of the mayor's race leaves of field of six candidates: Democrats Steven M. Costantino, John J. Lombardi, Angel Taveras, and Christopher F. Young and Independent candidates Jonathan P. Scott and Stephen L. Woerner.