Accsys had already signed an agreement with a Latin American board manufacturer for the production and sale of Tricoya modified panels.
The deal with INEOS is a 50:50 partnership in a new company, Tricoya Technologies, to boost the commercialisation of the material in the €60bn-a-year panel product market, a spokesperson said.
The two companies have also concluded a share deal worth €4m in which INEOS takes a 5.4% stake in Accsys.
"We are delighted to have joined Accsys in this new field," said INEOS CEO Peter Williams.
"The outstanding durability and stability of Tricoya offer the building industry valuable new options."
Accsys, which posted a €14.4m after-tax loss in the summer, has a licence deal with German chemicals group Solvay-Rhodia to build production plants for its solid wood Accoya.
