Fund management company VinaCapital, which owns a 37.8 percent stake in Ngoc Nghia, recently registered to sell it off.
Founder La Van Hoang and his family, who own 58.5 percent, have also registered to sell their stake.
Earlier Indorama Netherlands B.V., a subsidiary of Thailand’s Indorama Ventures, publicly stated its intention of buying Ngoc Nghia for an unspecified amount.
Indorama Ventures is the biggest plastic and polyester yarn manufacturer in Thailand and has made acquisitions in the U.S. and Europe to become one of the biggest players in the world.
The deal, if successful, would see a Thai company acquiring yet another Vietnamese plastic producer.
Last year, SCG Packaging Public Company Ltd bought a 70 percent stake in Duy Tan Plastics, the largest manufacturer of rigid plastic packaging products in Vietnam.
Most major companies in the plastic and paper packaging industry are foreign-owned, according to FPT Securities.
Ngoc Nghia was established in 1993 and mostly produces plastic bottles and medical containers, with Unilever, Coca-Cola and Vinamilk being among its top customers.
The company reported profits of VND103 billion ($4.5 million) last year.