Henrik Fisker, co-founder, executive chairman, and chief designer at Fisker Automotive speaks during the Chicago Auto Show, Feb 7, 2013. [Photo / Agencies]

The founder and executive chairman of Fisker Automotive Inc resigned from the cash-strapped "green car" startup on Wednesday, saying he was at odds with the automaker's top executives over business strategy.

Henrik Fisker announced his abrupt departure from the maker of the Karma plug-in hybrid in an email. He declined to describe the nature of the disagreements that prompted him to leave the company, which he founded with Barny Koehler in 2007.

"The main reasons for his resignation are several major disagreements that Henrik Fisker has with the Fisker Automotive executive management on the business strategy," the email said.

The surprise exit comes at a sensitive time for the US automaker, which has not produced a car since last July and is looking for a financial backer to buy a stake and help build its second model, the Atlantic plug-in hybrid.

The company is weighing bids from two Chinese automakers: Geely, the owner of Sweden's Volvo, and State-owned Dongfeng Motor Group Co, sources have said.

It is unclear how the exit of the Danish-born Fisker, 49, will affect this process. In a statement, Fisker Automotive said Henrik Fisker's departure would not change its strategy.

"The company has a strong and experienced management team and its strategy has not changed," the company said in a statement. "Mr. Fisker's departure is not expected to impact the company's pursuit of strategic partnerships and financing."

Finding a partner would lend the company credibility after last year's rocky and delayed introduction of the Karma, which starts at $103,000. A number of quality issues, including a recall of batteries made by A123 Systems Inc and a scathing review by Consumer Reports last year, hurt the Karma launch.

Delays in bringing the Karma to market last year prompted the US Department of Energy to bar Fisker from drawing down the rest of its $529 million federal loan.

'Very tough' choice

Fisker's exit is the most high-profile departure from the automaker, which has seen considerable turnover among its top ranks for more than a year.

In early 2012, Henrik Fisker stepped down as chief executive, giving that role to former Chrysler Group LLC CEO Tom LaSorda. LaSorda left in August, handing the reins to former General Motors Co engineer Tony Posawatz.

Henrik Fisker told Reuters in a brief telephone interview that leaving was a "very tough" decision. When asked if he would be an adviser to the automaker, Fisker said, "there have been no discussions at this point."

The former BMW and Aston Martin designer has been hailed for the look of the company's flagship Karma, a plug-in hybrid that counts pop singer Justin Bieber and actor Leonardo DiCaprio as owners.

But Fisker has been criticized for a lack of management experience and unrealistic business plan.

"He started something with a great idea but it just hasn't been able to get to that next level," AutoPacific analyst Dave Sullivan said.

"They've been sitting idle long enough," Sullivan added. "If there's any hope of wanting to save the company, now is the time to step down and let the experts revive the company."

Last week, Koehler told Reuters that the company is still a "couple months" away from resuming production of the Karma as it resolves issues with A123 which was purchased by Wanxiang Group, China's largest auto parts maker, out of bankruptcy.