Ben Good has, "by mutual agreement", departed as chief executive of D1 Oils, the turbulent oilseeds group which last week revealed it had lost a deal to be taken over by Australia's Mission NewEnergy.

Shares in the champion of the jatropha plant touched an all-time low in early deals.

D1 said that Mr Good, chief executive since December 2008, would leave after a handover period to Martin Jarvis, the group's chief operating officer, who is taking over the top job on an interim basis.

The company, in a statement which failed to include any comment by Barclay Forrest, the D1 chairman, said it acknowledged the "significant role [Mr Good] has played in restructuring and stabilising the business over the past two years".

"It has been a very difficult time for the company," a person familiar with the group said.

The departure follows the collapse last week of talks with Mission NewEnergy, a rival in the development of jatropha oil as a biofuel feedstock, after Brian Myerson, the veteran activist investor who is D1's biggest shareholder, vetoed the deal.

Unstable times 

Mr Good's exit also takes to four the number of D1 executives who have quit this year, following the departure in February of Moira Black and in March of Mr Myerson, who while chairman attempted to merge the company into a cane ethanol business in Mozambique.

Earlier this month, Nicholas Ward, a company restructuring expert, quit as a non-executive director after less than four months.

Besides fighting off Mr Myerson's takeover attempt, and his subsequent effort to sell or break up the group, D1 also in Mr Good's rein has seen the collapse of a joint venture with BP, the oil group, and undertaken a series of strategy shifts.

The company is still in the middle of a further strategic review, over which it said it planned "further discussions with major shareholders in the next few weeks".

It is also to continue talks with other, unnamed, suitors.

D1 shares touched an all-time low of 3.75p in early deals in London, before recovering to close at 4.25p, unchanged on the day.

The shares hit 565p in February 2005, not long after the group's flotation.