Seattle, Wash.-based Imperium Renewables announced today it would put its planned initial public offering on hold, less than two weeks after the biodiesel producer replaced its chairman and CEO in a pre-holiday shakeup (see Martin Tobias out at Imperium).

"Given the current market conditions, our board has determined that it is not the right time to pursue a public offering," said John Plaza, Imperium's founder, president and interim CEO.

The company announced that it would replace Martin Tobias on the Friday before Christmas, fueling speculation that it would delay its IPO, expected to raise up to $345 million.

No explanation was given for the replacement of Tobias.

Director Nancy Floyd, of investor Nth Power, has taken over as chair.

Other investors in Imperium include Technology Partners, Ardsley Partners, Attractor Investment Management, BlackRock Investment Management (UK), Capricorn Management, Ecofin, Robeco C.V., Silver Point Capital, Southport Energy Alternatives, Stark Biodiesel Investments and Treaty Oak Capital Management.

Imperium opened its first biodiesel plant in Grays Harbor, Wash., in August, capable of pumping out 100 million gallons per year, making it the largest biodiesel facility in the U.S. (see Imperium gets big with biodiesel).

The company was planning to list on Nasdaq under the symbol "IMPR." Imperium, which withdrew its filing with the U.S. Securities and Exchange Commission, did not disclose when it expected to make another run at the public markets.