Prudential's Class of 2011 research surveyed people planning to retire this year and found that the retirement income gender gap is £6,500.
The average woman retiring this year expects an annual income of £12,900 compared with an average male expected income of £19,400.
There is some good news for women though as the retirement income gender gap has shrunk since last year when Prudential's study showed a £7,400 gap with women expecting incomes of £12,200 while men looked forward to £19,600. But women who planned to retire in 2009 expected an annual retirement income of £13,700.
The research found that people planning to retire in 2011 expect to have an average income of £16,600 - marginally higher than 2010's figure of £16,500.
Vince Smith-Hughes, head of business development at Prudential said: "It is good news that average retirement incomes for women have risen, but unfortunately the gender gap remains stubbornly wide.
"There are a number of actions that women can take to help to boost their retirement income. For example, it is a good idea to maintain pension contributions during any career breaks and to explore making voluntary National Insurance contributions after returning to work.
"It is imperative for anyone looking to secure sufficient retirement income to start saving as much as they can, as early as they can and to seek professional financial advice in the run up to retirement."
The retirement income gender gap is at its widest in the South West of England where retired women expect £11,700 a year less than men. Meanwhile in the South East of England the expected retirement incomes for men and women are essentially equal.
The Prudential study also found that 28% of women planning to retire this year have no savings in private or company pension schemes compared with 10% of men.
Commenting on the findings, Joanne Segars, chief executive at the NAPF, said: "The big gap in retirement income between the genders is a serious issue, and the sums involved can make a huge difference to a pensioner's lifestyle.
"Sadly many women lost out on the chance to build their pension when they left work to start a family, and too many are reliant on their husband's pension. It's important that everyone has a pension in their own right.
"The gender gap may have narrowed slightly, but our society as a whole remains on a collision course with its retirement. Too many people are not saving, or are not saving enough. We have to get more people focused on putting something aside for their older age.
"Government plans for a simpler, more generous state pension should help, as will the introduction from 2012 of automatic enrolment into a workplace pension."
Prudential's Class of 2011 Survey conducted by Research Plus using an online methodology between 6 and 14 December 2010 among 10,143 UK non-retired adults aged 45+ including 1,005 planning to retire in 2011.