Major shareholder George Gould has been appointed chairman of Vertex after the surprise resignation of Jon Hartley last week.
Hartley stepped down on Friday, citing the toll of the plastics company's initial public offering and the investigations that followed.
Vertex's share price collapsed last September after a profit warning just nineweeks after listing on the Stock Exchange.
Two Australia-based directors, Simon Pillar and Barry Watts, also resigned on Friday to be replaced by Christchurch businessmen Humphry Rolleston and Kevin Arscott.
Gould, a South Island businessman, bought 19.9 per cent of Vertex last month and is already on the board.
Shares in Vertex closed unchanged at $1.44 yesterday, against a year high of $2.02 and a low of $1.10.
Gould is also managing director of rural services firm Pyne Gould Guinness and chairman of Designer Textiles.
He took a major stake in Vertex late last month, shortly before the company issued a second profit warning for the full year to March 31.
The company now expects earnings before interest and tax to be between $9.2 million and $9.6 million, compared with the September estimate of $10.1 million.
Gould said yesterday the board had agreed to apply a conservative approach to the business.
It will release a preliminary announcement for the March year on or about April 15.
* The mystery shareholder who dumped big volumes of Vertex stock in the week before the first profit warning is in the clear.
Average daily volumes of 100,000 swelled to 722,115 and 304,505 on August 27 and 28 - the week before Vertex announced a downgrade in projected earnings and revenue.
The Securities Commission said one unnamed investor sold "a considerable number" of shares.
After an investigation lasting more than six months, it did not find any links between the company's "insiders" - those who knew a downgrade was imminent - and those selling out.
An earlier investigation found the Vertex offer document did not adequately describe some risks.
The September profit warning triggered an immediate 25 per cent drop in share price, wiping $14.7 million from the company's market capitalisation.
The Shareholders' Association says legal action by one or more shareholders is a certainty.
