TORONTO -- Premier Doug Ford is facing criticism from both opposition parties after a $6.7-billion deal for Hydro One to acquire an American company was quashed.

U.S. regulators said they would not allow Ontario's largest utility to buy Avista Corp. for fear the provincial government -- Hydro One's largest shareholder -- might meddle in the utility's operations.

The regulators cited Ford's move to force the Hydro One chief executive to retire as proof that the province was willing to intervene in business operations.

Mayo Schmidt's early retirement was quickly followed by the resignation of the utility's entire board, as well as downgrades and lower values of Hydro One and Avista shares.

Late Wednesday, legislators from both the Opposition NDP and the former governing Liberals blamed Ford's Progressive Conservatives for the deal falling through.

Liberal MPP Mitzie Hunter said the message to Ford should be clear: "stop meddling at Hydro One."

But New Democrat Ian Arthur suggested the Liberals were also to blame, noting that Hydro One was partially sold off on their watch in 2015.

A spokeswoman for Energy Minister Greg Rickford defended the government's decision to make changes to Hydro One's executive, saying it was done in the interest of all Ontarians.