Irish-backed packaging group Ardagh has won US antitrust approval to buy Saint-Gobain Containers after agreeing to sell six of its nine glass container manufacturing plants in the United States, the Federal Trade Commission said.

The commission, which investigated the deal to determine if it was legal under antitrust law, sued in July to stop Ardagh’s proposed $1.7 billion purchase of Saint-Gobain’s US glass container business.

The agency had particularly focused on the prospect that the original deal could have led to higher prices for beer and spirits bottles.

The companies dominate the $5 billion US market for glass containers. The FTC had argued that the deal would combine the second-largest US glass container maker, the Saint Gobain unit, with the third-largest, Ardagh.

The result, the FTC said, was that newly combined Ardagh and number two, Owens-Illinois, would make more than 75 per cent of the beer and hard liquor bottles used in the United States.

As part of its deal to settle the litigation, Ardagh will sell six of the nine plants that it acquired when it purchased Anchor Glass Container Corp in 2012.

The sales must be completed within six months to a buyer approved by the FTC. "The proposed order creates a strong, independent third competitor that fully replaces the competition - in both the beer and spirits glass container markets - that would have been lost had the merger proceeded," Deborah Feinstein, director of the FTC's Bureau of Competition, said in a statement.

Saint-Gobain, which was founded in France in 1665 to produce mirrors for the royal court at Versailles, struck the deal in January to sell its North American glass container operation to Ardagh.

It plans to exit the low-margin business to focus on higher-margin building materials.