Windsor's apartment vacancy rate recorded the largest decline in Canada over the past year but still remains the highest in the country by a wide margin at 12.4 per cent.

It was 15.5 per cent in April 2009, according to figures released by the Canada Mortgage and Housing Corporation..

The second-highest vacancy rates in Canada were recorded in Peterborough and Abbotsford, B.C., each at 6.6 per cent.

Elsewhere across Canada, the average vacancy rate edged upwards slightly from 2.7 per cent to 2.9 per cent.

"Rental construction and competition from the condominium market added upward pressure on vacancy rates and historically low mortgage rates attracted renter households towards homeownership over the past year," said Bob Dugan, chief economist at CMHC's market analysis centre.

In Windsor, which has the lowest average housing price of any major metropolitan centre, apartment vacancy rates have been the highest in Canada for at least three years.

And Windsor's availability rate was also the highest in Canada at 15.9 per cent.

According to the CMHC, apartment availability means the vacant unit is ready for immediate rental or if the existing tenant has moved or given notice and a new tenant has not signed a lease.