Nabarro senior partner Simon Johnston is to step down after 12 years in the role at the helm of the firm.

Johnston's decision was announced today (13 September), and he will step down at the end of the calendar year.

A new senior partner-elect is expected to be in place by the time of firm's partner conference in mid-November with partners able to put themselves forward from now onwards.

His successor will formally take up the post in January 2013, with Johnston remaining with the firm for some time to help with the transition.

Johnston was re-elected for a third five-year term in February 2011, having intially become senior partner in 2001 at the age of 39, when he was the youngest-ever partner to head the firm.

He has led Nabarro through a difficult recession, with the firm carrying out a restructuring during the last financial year which saw 17 partners cut from the equity.

The restructuring helped the firm to first increase in profits per equity partner (PEP) since 2007-08, with 2011-12 PEP rising 4.4% to £332,000. This compares with a high of £610,000 in 2007-08 and came against a marginal increase in turnover in 2011-12, taking revenue to £113.4m.

It is understood Johnston had always considered a partial third term, with the end of the restructuring and the fact the firm has now largely sorted out its London office move planned for November 2014, allowing him to step down.

Johnston (pictured) said: "This has been a very difficult decision for me to make. I had originally intended to step down in 2010 after two terms in the role, but did not feel then that it would be in the best interests of the firm to hand over the reins given the general economic climate and that we were involved in detailed discussions regarding our London head office property needs. Given we are now growing both the top and bottom line, and we are in the process of finalising our property needs, I am now able to take this step."

"I have a great affection for Nabarro and I am proud of what we have achieved. It is a fantastic firm, with talented people throughout the organisation and a strong client list. Although I will miss the job, the time is now right to bring a fresh perspective to the leadership of Nabarro and, with our legal market rapidly changing, it is appropriate for the firm to have as senior partner someone who can commit to staying with the firm in the longer term. It will also give me the chance to explore some of the opportunities that have been presented to me over the last few years outside the law."

Former managing partner Nicole Paradise stepped down last summer – also after 12 years – to be replaced by Andrew Inkester.