The chief financial officer of FTSE 250 company Lamprell has announced his departure from the oil rig maker on the day before its financial results are due out.

Frank Nelson said he was leaving the company for 'personal reasons'. He will step down officially on 1 October and is to be replaced by Joanne Curin, a non-executive director with WS Atkins and Deep Ocean Group Holdings.

Nelson joined Lamprell less than a year ago after retiring as finance director at housebuilders Galliford Try. He was initially appointed as interim CFO but the role was made permanent in March and it was understood he would stay for some time.

Shares in Lamprell dropped by more than 4% on the news of Nelson's departure. The Dubai-based company has experienced a turbulent 12 months, after operational difficulties resulting from moves into riskier areas such as wind turbine vessels, saw it issue five profit warnings over seven months last year.