The average age of gay couples entering civil partnerships was more than a decade older than the average age of heterosexual couples marrying , figures released by the Central Statistics Office (CSO) for 2011 haves shown.
The figures released today are the first detailed statistics relating to the 2011 introduction of civil partnerships for gay couples in Ireland.
Ceremonies began in April of that year.
It shows the average age of partners in the 536 couples entering civil partnership was 44.3, (44.7 for men and 43.8 for women).
This compares with 34.6 years for a groom entering marriage and 32.5 years for bride.
The average age of marrying couples has continued to increase and in 2011 rose by half a year since 2010.
The CSO figures show that the number of marriages has continued to fall and reached the lowest level since 1998 to 4.3 per 1,000 of the population. There were 19,855 marriages registered in 2011 and 20,594 in 2010.
Of the 536 civil partnership ceremonies held in 2011, 335 were male unions and 2011 were female unions the figures show.
Over 70 per cent of couples who entered civil partnerships in 2011 lived in Leinster.
Of the couples living in Leinster a third lived in Dublin city, almost a fifth in the greater Dublin area.
Outside of the capital, Cork had the highest number of civil partnerships in 2011 (6 per cent).
Just one civil partnership was registered in each of North Tipperary and Monaghan.
Over 95 per cent of civil partners were previously single with 4 per cent divorced and others widowed.The figures show a 1 to 4 year difference in ages in a third of male partnerships and in 43 per cent of female partnerships.
In heterosexual marriages in 2011 the couples joined by civil ceremony tended to be older than those going through a Roman Catholic ceremony.
In civil marriages the average age of the groom and bride were 37.9 years / 35 years respectively compared with 33.1 years/31.3 years respectively for the average age of a Roman Catholic groom and bridge.
In 2011, civil marriages were the most common form of marriage ceremony for grooms aged 45 (69 per cent) and for brides aged 40 and over (67per cent).
In Dublin almost 43 per cent of couples had civil marriages compared with just a fifth in the border region.
The proportion of different types of marriage ceremony remained broadly similar in 2011 with two thirds Roman Catholic, 29 per cent civil marriages .
The figures also showed a continued decline in the number of divorces registered with the courts, which fell by almost a tenth (9 per cent) since 2010.
There were 2,819 divorces granted, a decrease of 294 on 2010.
It was a third less than the number of divorces granted in 2008.