Moisson retired from the Morgan Cole partnership at the end of last year after reaching the retirement age of 60, but has since resurfaced at Boyes Turner as a consultant.
He was formerly the senior partner of Cole & Cole and was responsible for steering his Reading firm through the merger with Welsh giant Morgan Bruce. In conjunction with co-chair Guy Clarke, he was responsible for instigating a partner cull to boost profits after the merger. He stepped down from the chairmanship on 1 November 1999.
The departure follows that of a number of senior figures in recent months.
In January, The Lawyer reported that Morgan Bruce business services partner Alun Cole and head of planning and environmental Julian Boswell are both set to join the Cardiff office of Eversheds.
Cole (no relation to the founding partners of Cole & Cole) is believed to have been close to former partners Jeff Jenkins and Duncan MacIntosh, who have just departed for Clark Holt and Palser Grossman respectively (The Lawyer, 8 December).