DETROIT — Ally Financial Inc., the former finance arm of General Motors that was bailed out by the US government, is selling its Canadian auto finance unit to Royal Bank of Canada for $4.1 billion.

The deal, expected to close early next year, is part of Ally’s plan to accelerate repayment of the $17.2 billion bailout, but it was unclear Tuesday exactly when the government would get more money. So far Ally has repaid $5.8 billion. The US Treasury owns 74 percent of Ally common stock plus $5.9 billion of preferred stock.