Equity partner headcount among the UK's 50 leading law firms grew by 3.7% across the group in 2013-14, with the impact of global mergers helping to bulk out the numbers.

Half of the top 50 increased the size of their equity partnerships, with Ashurst and Herbert Smith Freehills (HSF) showing the largest increases in the wake of their tie-ups with Australian firms.

Of the other half, Eversheds saw the biggest dip in equity partner count, with its figure of 118 representing an 11.3% decrease on 133 in 2012-13. Total partner count at the firm was down 5%. 

The firm would not be drawn on whether its numbers were affected by a restructuring carried out at the start of January 2013, when a redundancy programme affected 166 roles. Eversheds chief executive Bryan Hughes says equity partner count was lower last year "for a variety of reasons", and that he expects numbers to increase this year as a result of promotions and lateral hires.

top-five-firms-equity-partnership

Berwin Leighton Paisner was the other firm to suffer a double-digit fall in equity partner numbers, dropping by 10.1% to 91.6. It carried out a redundancy programme last spring that resulted in the loss of 102 fee-earning and secretarial roles – a move that also led to a decrease in average total partner count of 4% to 212.9.

Slaughter and May experienced the biggest fall in equity partners of any of the magic circle firms after numbers fell by 6% to 109.5. This was in part down to several long-serving partners opting to retire during the year, including former executive partner Graham White and corporate partners Charles Randell and Kathryn Davis.

Practice partner Paul Olney (pictured) says: "I wouldn't read too much into one year's movements; for example, we made up seven new partners in London in May and a further four in Hong Kong during this year – the largest number of promotions we have made for many years. paul-olney

"In general, however, the reduction in 2013-14 reflects a combination of personal decisions and demographics as several partners reach the age where, statistically, they will consider retirement."

Other firms posting a significant decline include Bird & Bird, which logged a drop of 8.9% in 2013-14, with equity partners falling from 101 to 92 despite a 12% growth in total partner count. A spokesman for the firm denied there was a partnership restructuring, but said there was a higher proportion of junior partners coming through the ranks that would have affected the numbers.

It comes as little surprise that Ashurst and HSF bulked up their equity partner ranks the most over the last year. Ashurst grew average equity partner headcount by 69%, with the number rising from 155 to 262 on the back of its tie-up with Australia's Blake Dawson, which formally took effect last November.

Similarly, legacy Herbert Smith's combination with Australian firm Freehills in October 2012 has resulted in a hike of 32.1% in equity partner numbers following the integration of the two partnerships. 

Fieldfisher, Olswang and Gateley are among other firms to see significant growth in their equity partnerships during the financial year, increasing by 22.8%, 17.8% and 14.3% respectively.

Fieldfisher managing partner Michael Chissick says its expanded equity partnership came on the back of an "extensive lateral hiring programme" that saw 25 lawyers join as partners during the financial year, with the majority joining the equity upon arrival. The increase, which accompanies a 2.7% rise in total partner numbers, also factors in the firm's April tie-up with eight-partner Manchester boutique Heatons.

A spokesperson for Gateley confirmed its increase is "largely a result of promotions from fixed-share to full-equity partnership" taking effect during the year. The firm added an average of nine equity partners during 2013-14. 

The overall number of partners across the top 50 also grew, up 6.2% from 9,871 to 10,486.