The community of Smiths Falls, Ont. is gearing up for a public rally on Saturday in an attempt to keep a chocolate factory from closing, leaving more than 500 people without jobs.

The Canadian Auto Workers union announced the rally on the same day that Hershey Co. told employees that the facility would be closed later this year.

Union representative Harry Ghadban said the rally will go ahead at 10 a.m. even though the U.S.-based company has confirmed their plans.

Premier Dalton McGuinty has also tried to intervene. He spoke with Hershey's CEO Richard Lenny, but said the chocolate manufacturer was not receptive to an offer of help from his government.

"I asked if there's anything that we might do at this point in time," McGuinty said from Ottawa. "They just don't seem to be particularly receptive to that."

The Hershey plant is the largest employer in Smiths Falls, a community of about 9,000. The company said a "supply chain realignment" is behind the decision to close the 44-year-old plant.

A phased shutdown is expected to begin this year, with some operations continuing through 2008.

News of the closure came just three months after workers were forced off the job when Hershey voluntarily recalled some of the products manufactured in Smiths Falls over concerns about salmonella contamination.

The entire plant was shut down while the source of the contamination was investigated. Hershey gradually brought back about 200 employees to help sanitize the plant, but the rest remained off the job throughout the closure.

The salmonella was traced to a supply of soy lecithin used in many of Hershey's products.

There were no reports of illness as a result of the salmonella contamination.

With files from The Canadian Press