Atlas Arteria, an Australian toll road company, has agreed to buy a 67% stake in the Chicago Skyway from two Canadian pension funds for $2 billion.

The deal, announced Tuesday, would give the publicly traded firm majority control of the 7.8-mile elevated toll road connecting the Dan Ryan Expressway to the Indiana Toll Road on Chicago’s South Side, pending approval from regulators and the city.

Canada Pension Plan Investment Board and OMERS Infrastructure, which each bought one-third stakes in the Skyway six years ago, agreed to the sale Monday. Atlas Arteria, which owns toll roads in France, Germany and Virginia, will partner with Ontario Teachers’ Pension Plan, which is retaining its one-third stake.

Built by the city in 1958, the six-lane Chicago Skyway features a steel bridge spanning the Calumet River, and a congestion-easing shortcut to Indiana and points east. The city operated the Skyway until 2005, when it leased operations to a private company under a 99-year agreement, marking the first privatization of an existing toll road in the U.S.

In 2016, the three Canadian pension funds bought Skyway Concession, the toll road’s private operator, for $2.8 billion.

Atlas Arteria, which owns the Dulles Greenway, a 14-mile toll road that connects Washington Dulles International Airport with Leesburg, Virginia, has come under fire from its largest shareholder for plans to buy a second toll road in the U.S.

IFM Investors, an Australian investment firm that owns a 15% stake in Atlas Arteria, has opposed the potential Skyway acquisition since becoming the company’s largest shareholder in June. In a letter sent Monday to Atlas Chair Debbie Goodin, IFM called the Skyway purchase “highly dilutive to distributions” and “value destructive,” urging the company to withdraw from the Chicago toll road acquisition process, and warning of an “accelerated board transition” if it moved forward.

The investment firm issued a statement Tuesday following the announcement that Atlas had agreed to purchase the Skyway over its objections.

“We are disappointed with the decision by Atlas Arteria to proceed with the acquisition of the Chicago Skyway, and as a major shareholder we are considering our options,” an IFM spokesperson said.

The Skyway was a money-loser for decades after it opened to traffic in 1959 and only began generating a profit in the early 1990s, when convenience trumped the cost for a growing number of motorists, and the toll road traffic dramatically increased. The city began exploring a Skyway sale to private operators in 2002 under then-Mayor Richard M. Daley, seeking money to pay off several hundred million dollars in outstanding bonds for the toll road.

In 2004, the city struck a groundbreaking $1.8 billion deal to lease the Skyway to a Spanish-Australian consortium for 99 years. As part of the agreement, the city set limits on graduated increases for the toll, which then cost $2 per trip. Skyway Concession has invested more than $130 million in improvements since taking over the toll road, including adding an electronic payment system.

The current rate for a car is $5.90 per trip, with average daily traffic at about 38,000 vehicles, according to Skyway Concession.