Syngenta, the world's biggest seed and herbicides group, has appointed as chairman a former executive at rival Dow Chemical to replace Martin Taylor, who is to step down after 13 years.

Syngenta - formed from the merger of Switzerland's Novartis with the UK's Zeneca - has turned to a Belgian, Michel Demaré, as its chairman, set to take office as of April.

Mr Demaré, 56, joins from ABB, where he has been chief financial officer for 2005, and where in 2008 served a spell as interim chief executive after the surprise departure of Fred Kindle over "irreconcilable differences" with the Swiss engineering group's board.

Mr Demaré also worked for 18 years at Dow Chemical, the US-based chemicals conglomerate, and one of the major competitors to Syngenta, along with the likes of BASF, DuPont and Monsanto.

'Outstanding track records'

ABB - which said that Mr Demaré was quitting to "concentrate on his board mandates", which also include vice-chairmanship of board at Swiss bank UBS – said he had brought "energy and professionalism" to his post.

"He has had outstanding track records during his time at ABB. The company's strong financial position is testimony to his achievement," ABB said.

At Syngenta, where Mr Demaré was appointed a director in April, Mr Taylor said he was "delighted" at the appointment.

"Since his election as a director he has already made a significant contribution to Syngenta," Mr Taylor said, adding that Mr Demaré's international experience "makes him exceptionally well-qualified for the position".

Syngenta employs more than 26,000 people in more than 90 countries.

He will become only the second chairman of Syngenta, which Mr Taylor, a former head of UK-based Barclays Bank, has chaired since its formation in 2000.

Syngenta shares closed 0.7% higher at SFr347.30.