A jury award of nearly $1 million to former WSVN-Fox 7 health reporter Marilyn Mitzel for age discrimination at the hands of station management was wiped out Wednesday by an appellate court.

The Third District Court of Appeal reversed the 2010 jury finding that Sunbeam Television Corp., WSVN’s owner, fired Mitzel three years earlier because she was too old for television, and ordered a Miami-Dade court to reconsider the case.

The appellate court ruled that the trial judge shouldn’t have allowed Mitzel to add a charge of sex discrimination to her lawsuit late in the case. And it was harshly critical of an expert witness who testified on Mitzel’s behalf, saying her “testimony reached beyond the scope of this case to come to conclusions she was not competent to reach, and served only to interject irrelevant conjecture into the jury’s consideration.”

William Amlong, Mitzel’s attorney, shrugged off the ruling. “We would like to have won it, obviously,” he said. “But we’ve won this trial once, and now we’ll go back and win it again.”

But Michael Casey, Sunbeam’s attorney, said he’ll move for an immediate dismissal. “Today’s ruling essentially eliminated their whole case,” he said.

Mitzel, once a ubiquitous presence on WSVN — her health and medical news segments aired eight times a week, and she was also a back-up anchor — was 52 years old when WSVN fired her after 17 years at the station. She testified at the trial that WSVN didn’t offer any reason for her dismissal. But she noted that she lost her anchor duties after she turned 50 and believed that her age also played a key role in her firing.

Her testimony was supported by Sherlynn Howard-Byrd, chairman of the communications department at Alcorn State University in Mississippi, who told the jury that WSVN staffed its stations with “ ‘sweet young things’ rather than seasoned professionals.”

WSVN executives countered that they got rid of Mitzel only because television audiences were more interested in news about terrorism and politics after the Sept. 11 attacks.

The appellate court said that Mitzel waited too long — two and a half years into her case — before adding the charge of sexual discrimination to her suit. And Howard-Byrd’s testimony, the court said, amounted to nothing more than “an unsupported running theory that age discrimination against women is pervasive within the broadcast news industry” rather than specific evidence against WSVN.

Mitzel briefly took a job at a North Dakota station after leaving WSVN but soon returned to South Florida and has done little work in television since.