HONG KONG: Asia's millennials face a financially uncertain future as, sandwiched between looking after ageing parents and bringing up their own children, many are failing to provide for their own retirement.

The findings emerged from the Manulife Investor Sentiment Index, from the financial services group and based on 500 online interviews each in Hong Kong, China, Taiwan, Thailand, Singapore, Malaysia and the Philippines, and 500 face-to-face interviews in Indonesia, with middle class respondents who already have investment products.

Nearly three in ten in this financially savvy group expected to run out of money in retirement, while almost four in ten anticipated carrying mortgage debt into their retirement years.

On average, millennial investors expected to accumulate just 8.2 times their annual income by the time they retired, compared to the typical benchmark figure of 25 times.

"They are the sandwich generation — no sooner have they financed their children's education, they have to support their ageing parents," said Roy Gori, president and CEO of Manulife Asia.

And, he told CNBC, the combination of slower economic growth and longer parental life expectancy of their parents was having an adverse effect on their own retirement planning.

"This a double-edged sword because millennials themselves are less likely to receive financial support from their own children when they are aging," Gori said.

He argued that the traditional approach of investing in property first and putting anything over left in bank deposits was not a viable strategy in an era of low interest rates and maturing real estate markets, and suggested that millennials now needed to take more risk and invest in equities.

Gori further highlighted the changing nature of the world of finance when he observed thatAsians used to be known as the prudent consumers with the lowest levels of debt. "Today, that's no longer true," he said.

"In some cases, the level of indebtedness we see in Asia either equals or exceeds that of US consumers, measured by household debt relative to disposable income."

Data sourced from CNBC; additional content by Warc staff