Samsung is downsizing the workforce at its last remaining smartphone plant in China due to sluggish sales and rising labor costs.

Chinese economic newspaper Caixin reported on Wednesday that Samsung is taking applications for voluntary redundancy from staff at the plant in Huizhou, Guangdong Province, until June 14, though the scale is not known.

On the same day, Samsung confirmed the reports, saying, "We are trying to adjust production and reduce personnel for efficiency in management."

The Huizhou plant is now Samsung’s only plant in China. It was opened in 1992 and started producing smartphones in 2006. As of 2017, it employed some 6,000 workers and produced 62.57 million smartphones.

Due to struggling sales in the country, the Korean electronics giant shut its plant in Shenzhen in April last year and another one in Tianjin in December.

The average monthly wage at the Huizhou plant nearly tripled in 10 years from 1,894 yuan (about W320,000) in 2008 to 5,690 yuan (about W970,000) in 2018 (US$1 = W1,179). While the company said it has no plans to close it down, industry observers say it is possible Samsung will completely withdraw from China and move to Vietnam, which currently accounts for 40 percent of Samsung’s global output.