Figures show that 6,281 gay couples had civil partnerships in the UK in 2009, a fall of 12 per cent compared with 2008.
According to the Office for National Statistics, 3,227 male and 3,054 female couples tied the knot last year.
Between 2005, when the law came into force, and the end of last year, a total of 40,237 gay couples had civil partnerships.
The number of ceremonies peaked in 2006 and have been steadily declining since in England, Wales and Scotland after the initial rush.
But in Northern Ireland last year, there was a 12 per cent rise in the number of ceremonies.
As with previous years, the areas with the highest number of civil partnerships formed were the London borough of Westminster and Brighton.
Last year, the average age for having a civil partnership was 41 for men and 38 for women.
To obtain a civil partnership dissolution in the UK, a couple must have been in either a registered civil partnership or a recognised foreign same-sex relationship for 12 months.
In 2009, 351 civil partnership dissolutions were granted, of which 127 were to male couples and 224 to female couples. In 2008, 180 couples dissolved their civil partnerships.