Construction services group Carillion has shaken up its senior team in a move which sees its finance head and former chief executive leave the business.

Group finance director Zafar Khan has left with immediate effect, with Emma Mercer appointed chief financial officer.

Since joining the Wolverhampton-based group in 2008, she has held several senior positions, most recently finance director of the UK construction business prior to which she was chief financial officer and senior vice-president of Carillion Canada.

Former chief executive turned chief operating officer Richard Howson will leave this month, as will managing director of Carillion Construction Services Adam Green and managing director of Carillion Services Nigel Taylor.

Shaun Carter, group strategy director, will leave the company by the end of the year.

Mr Howson stepped down from his chief executive's post in July after the listed group issued a profit warning to the stock exchange which wiped almost £600 million off the value of its share price.

Elsewhere, Lee Watson has been appointed chief transformation officer on secondment from accountancy group EY where he has been a partner since 2008 during which time he has advised on numerous transformations and restructurings for UK companies.

Andy Jones, currently president and chief executive of Carillion Canada, has been appointed chief operating officer and will take up this role in October.

Carillion offered no comment or further explanation about the appointments and departures in a brief update to the stock exchange.

The group led the development of the Library of Birmingham and has also been appointed as a contractor on the Paradise regeneration project in the city centre and tunnels for the new HS2 high-speed rail line.