On June 14, 1991, he formed a public-private partnership of 13 investors to buy the team and prevent a threatened move to Arizona. He used C$2 million from his own funds to make this purchase. He was the largest shareholder, with 7% of the shares, and became managing general partner.
However, the team's other partners considered their investments to be charitable donations, and refused to commit any more money beyond their initial investment. As a result, even though Montreal was the fifth-largest Brochu was forced to run the Expos on a shoestring budget. Despite this, the Expos managed to assemble a core of players that included Moises Alou, Marquis Grissom, Larry Walker and John Wetteland. In 1994, those players, led by manager Felipe Alou, had the best record in the majors when the strike cut the season short. They were poised to run away with the National League East, with most projections having them winning as many as 105 games.
In the 1994-95 offseason, Brochu ordered general manager Kevin Malone to cut ties with several of the stars of that season. In a series of transactions that took place between April 5-8, Wetteland was traded to the New York Yankees, Ken Hill to the St. Louis Cardinals, and Grissom to the Atlanta Braves. Walker was a free agent, and the Expos allowed him to go to the Colorado Rockies without getting anything in return. The fans and press were savage in their condemnation of the fire sale. Years later, Brochu told writer Jonah Keri that he didn't want to unload Wettland, Hill, Grissom and Walker, but had no choice due to a dangerous depletion of capital. He'd asked the other partners to contribute more money, but they all turned him down.
In 2001, he published the book My Turn at Bat: The Sad Saga of the Expos, which blamed Quebec ex-premier Lucien Bouchard for the sale of the baseball team. Bouchard had told him that he wasn't willing to authorize public funding for a new park when he was being forced to close hospitals.