(Reuters) - Mississippi's sole abortion clinic will remain open after a federal appeals court refused on Thursday to reconsider its decision to block a state law that would have closed it.

The law, passed in 2012, required doctors at the state's sole abortion clinic to have admitting privileges at local hospitals, a standard the clinic could not meet.

A three-member panel of the 5th U.S. Circuit Court of Appeals in July upheld a lower court ruling blocking the law as a legal challenge continues. On Thursday, the appeals court denied Mississippi's request for a reconsideration of the injunction by the full court.

"This is definitely good news," said Diane Derzis, who owns the Jackson Women's Health Organization, the only abortion clinic in Mississippi. "We've been waiting so long. It's a true Thanksgiving."

Mississippi is among several states that have passed laws requiring abortion doctors to have admitting privileges at a hospital within 30 miles of their clinic.

Abortion rights campaigners say the laws, some of which are under court review, impose medically unnecessary requirements targeting providers of the procedure.

Anti-abortion advocates have countered that they are intended to protect women's health, though some have also said they would likely shutter clinics.

"There are a lot of places women can go if they want an abortion," said Tanya Britton, a board member of Pro-Life Mississippi. "They can go to Louisiana. They can go to Arkansas. They can go to Alabama."

Many hospitals refused to consider the admitting privileges applications of doctors working for the Jackson Women's Health Organization, which nearly closed as a result. 

A federal district court judge in 2012 issued a temporary injunction blocking the law because it would have forced women seeking abortions to go out of state. The same judge issued a second injunction in 2013 that remains in effect with Thursday's order.

Advocates who brought the suit against Mississippi's law expect it to move forward at the trial court in 2015. The state also has the option of asking the U.S. Supreme Court to lift the injunction.

(Reporting by Emily Le Coz; Editing by Jonathan Kaminsky and; Eric Beech)