The company's Class of 2012 study, which looks at the finances and expectations of those planning to retire this year, found 48% of men and 32% of women would be happy to continue working past the standard retirement age.
The main motivation for more than two thirds (68%) of this year's retirees who want to stay in the workforce past 65, is a desire to remain physically healthy and mentally active, while 39% do not like the idea of retiring and just staying at home. More than half (54%) enjoy working.
But despite wanting to stay in work, only 13% would choose to continue to work full-time with their current employer.
Nearly half (49%) of those retirees who want to work past 65 years old would prefer to work part-time, either with their current employer or in a new role, in order to strike a better work life balance.
More than one in 10 of entrepreneurial retirees would consider starting their own business after the age of 65 or earn money from a hobby in order to keep working. Five per cent would work as charity volunteers.
ONS figures show average retirement ages are rising, with men now retiring at an average age of 64.6, compared with 63.8 in 2004, and women working until 62.3 years compared with 61.2 previously.
Vince Smith-Hughes, retirement expert at Prudential, said: "There is a new retirement reality taking shape across the UK, with thousands of people actively choosing to work past the traditional retirement age.
"The fact that so many of this year's retirees would keep working on a part-time basis is a strong indication that, for many, working is as much about staying young at heart as it is about funding retirement.
"Gradual retirement is an increasing trend among pensioners, whether this means remaining in the same job on a flexible basis or even setting up their own business! Those retiring at 65 will face an average of nineteen years in retirement which makes the financial and social benefits of working for longer an even bigger draw for a new generation of industrious retirees."
The online survey conducted by Research Plus between 2 and 12 December 2011 among 9,614 UK non- retired adults aged 45+, including 1,003 retiring in 2012.
