Louis for US$20 million (euro17 million).
In a statement, Vitro said it plans to use cash from the sale of its 51 percent stake in Quimica M to pay down debt. The sale requires regulatory approval in both Mexico and the United States.
Vitro said that 2004 sales at Quimica M totaled US$47 million (euro40 million).
The facility in central Mexican city of Puebla produces polyvinyl butyral for laminated construction and automotive glass.
In a separate statement, Solutia said it has secured commitments from Vitro so that the Monterrey-based company will continue buying plastic interlayers from Quimica.
Vitro - whose main businesses are flat glass, glass containers and glassware - had net debt of US$1.3 billion (euro1 billion) at the end of September. The company has been shedding assets in recent months in an effort to meet those obligations.