In June I will be in Toronto, and am looking to hire a rental car, drive through Quebec then onto Maine and eventually return the car at Boston ,16 days later. I am finding it difficult to find a rental company that is willing to accept this hire. Any suggestions or recommendations?

highly doubt you'll find a company that will do one way between two countries. good luck.

Try Hertz. I know a few years ago that Hertz would rent in Canada and drop off in the USA. Probably works in reverse.

I have heard that Hertz might do it but am waiting for their rates for June to come out.

you could save by picking up a rental on the US side of the border and driving back through Canada...

Here's how it works... several of the rental companies allow Toronto rentals to be dropped at Niagara or Buffalo Airport locations... grab a one day in TO and drive down to Buffalo... leave that car there and shuttle to the agency that offers you the best rate on a Buffalo to Boston drop off... then drive back through Canada on your trip...

one way to beat the system... good luck