ROCKLAND, Maine — The job cuts announced earlier this week at the FMC plant in Rockland total 13, a company spokeswoman said Friday.

The jobs were eliminated through a combination of layoffs and open positions that were not filled, according to FMC marketing communications manager Lindsay Torriero. Three full-time employees and one part-time worker lost their job, she said.

With the cuts, the workforce at the Rockland plant is down to 107. The company remains one of the largest employers in Knox County and is the largest property taxpayer in Rockland.

FMC’s plant on the Rockland waterfront manufactures carrageenan, which is a common food additive extracted from seaweed and used as a thickening agent and stabilizer in such items as whipped cream, yogurt, ice cream, toothpaste and gelatin products.

Without specifying how many jobs were being cut, the company announced earlier this week that the workforce reduction was necessary for the plant to stay competitive and adapt to evolving market conditions.

“The carrageenan product line produced in Rockland remains critical to FMC. Ensuring that we have the right structure in place and can remain cost-competitive will help this site and the business thrive,” the company letter stated.

The Rockland plant has operated since 1936, when the Algin Corporation opened the facility. It is now the only carrageenan manufacturing plant in North America, according to FMC’s website.