TORONTO -- An increasing number of Canadians surveyed in a BMO study have invested in a registered retirement savings plan this year.

The BMO Financial Group survey found 67 per cent of respondents have an RRSP, compared to 61 per cent at this time last year.

And nearly three-quarters of survey respondents plan to contribute the same amount or more to their RRSP than they did last year.

Among those who do not have an RRSP, half say they plan to open one in the next five years.

And about 74 per cent of respondents have already made or plan to make a contribution toward an RRSP before the 2012 deadline, five percentage points higher than last year.

Last year's average contribution amount was $4,670.

The study found that a number of Canadians -- 68 per cent -- were worried about the health of their RRSPs given the volatility of stock markets over the last two years.

"It's encouraging that a growing number of Canadians understand the important role an RRSP can play in preparing for retirement," said Marlena Pospiech, senior manager at BMO Wealth Planning Group.

"But it's sobering that so many are worried about the performance of their investments within their RRSP."

The survey was conducted online among 1,000 Canadians between Nov. 23 and Nov. 27.

The polling industry's professional body, the Marketing Research and Intelligence Association, says online surveys cannot be assigned a margin of error because they do not randomly sample the population.