More than 150 opposite-sex couples formed civil partnerships on the first day they were legally able to do so, figures show.
There were 167 opposite-sex civil partnerships formed on 31 December 2019 in England and Wales, the Office for National Statistics (ONS) said.
This was the first day it was possible to do so after legislation extended civil partnership rights to opposite-sex couples.
It is the first time civil partnership statistics for England and Wales in 2019 have been published.
The ONS said it expects to see the overall number of civil partnerships rise as more opposite-sex couples choose this option.
The number of same-sex civil partnerships fell in 2014 and 2015 following the introduction of same-sex marriages in March 2014 and has remained stable since then.
More men than women have formed civil partnerships each year since then, likely a consequence of more female couples choosing to marry.
Over 2019, there were 994 same-sex civil partnerships formed – up 4% from 956 the previous year.
The ONS said the annual increase was driven by a 15% rise in the number of female partnerships.
More than half (61%) involved men, half of those entering into civil partnerships were aged 50 and over, and nearly a fifth (19%) were aged 65 and over.
Around three-quarters of the same sex civil partnerships formed in 2019 involved partners who had not previously entered into a marriage or civil partnership.
Over the year, 916 civil partnerships were dissolved – a fall of 30% from 1,313 dissolutions in 2016.
The decrease is likely to be a consequence of many same-sex couples choosing to marry or convert their existing partnership into a marriage.