The flagging agrichemicals sector saw a second chief executive quit in three days, as Daniel Leever announced his departure from Platform Specialty Products, days after a second profits warning.
Mr Leever is to retire as chief executive of Platform Specialty Products, the owner of Arysta LifeScience, after two years in the post.
"I strong believe that it is the right time for a new person to take over the reins of day-to-day operations, and to be able to set out a clear execution strategy," Mr Leever said.
The statement follows Wednesday's announcement by Syngenta, the world's biggest agrichemicals group, of the departure of its chief executive Mike Mack, who said it was "an appropriate time for the company to benefit from the perspectives of a new leader".
However, shareholder reaction to the departures was markedly different.
While Syngenta shares, which stood at SFr335.40 in late deals on Friday, have gained 8% since Mr Mack's resignation, the news of Mr Leever's retirement sent Platform Specialty Products' New York-listed stock tumbling by 19.8% at one point to $9.25.
That was the lowest price since Platform Specialty Products shares listed in January last year.
The stock recovered some ground in late morning deals to stand at $10.61, a drop of 8.0%.
Martin Franklin - the serial dealmaker who founded Platform Specialty Products in 2013, and remains chairman - said that Mr Leever had played a "pivotal role" in the creation of the company, which has been formed by knitting together specialty chemicals groups including Arysta and Agriphar.
"It is a testament to his energy, passion and 'builder' mentality that Platform's annualised, pro forma revenues will have grown fivefold from 2013 to 2015."
However, Mr Franklin added that, with finalisation pending on the takeover of Alent, the UK-based coatings group, "we respect Dan's decision that it is the right time for a new generation of leadership to continue the vision".
Mr Leever joined Platform Specialty Products with the group's first acquisition, the $1.8bn purchase of MacDermid, of which he had been chief executive, and which makes everything from hydraulic fluids for vehicles to chemicals for computer printed circuit boards.
However, Platform Specialty Products, which a year ago bought Arysta for $3.5bn, has been weighed down by its investments in the agrichemicals sector, undergoing a high-profile downturn which has seen peers such as FMC Corp also cut profit hopes, and sparked a wave of deal speculation as groups attempt to consolidate and cut costs.
Andrew Liveris, the Dow Chemical chief executive, said on Thursday that "everyone is talking to everyone" in the sector, as he revealed that the US chemicals leviathan was to "review all options" for its farm sprays and seeds division.
Platform Specialty Products two weeks ago unveiled its second profits warning in two months.
Agrichemicals producers have been hit by the dent to farm spending from lower crop prices, with a strong dollar too undermining export prospects, particularly to the major farm economy of Brazil, where currency weakness has made imported farm inputs less affordable for growers.
Brazilian fertilizer industry association Anda this week reported a 21% slump, year on year, in the country's fertilizer imports in September.