Green Nikola Holdings, a subsidiary through which Hanwha holds its 5.65% stake in Nikola, is planning to sell up to 11.1 million shares, according to a securities exchange filing.

The shares will be worth about $180 million based on Nikola's last closing price of $16.39.

A Hanwha Group spokesperson said it will use the proceeds to invest in hydrogen-related businesses, adding that the potential sales is not an end of cooperation with Nikola.

Hanwha Group first acquired a stake in November 2018, much before Nikola debuted on the Nasdaq in June last year. The company's shares have since then nearly halved in value.

Nikola and its founder Trevor Milton were subpoenaed by the U.S. Department of Justice in November last year following allegations of fraud by short-seller Hindenburg.

It claimed that Milton, who has since resigned as chairman, had made false claims about the company's proprietary technology to form partnerships with large automakers.

The company is also being investigated by the U.S. Securities and Exchange Commission and the U.S. Attorney's Office for the Southern District of New York in connection with the allegations.

Last month, following an internal review, the electric-truck maker said the company and its founder Trevor Milton had made several statements that were partially or completely inaccurate.

"Hanwha remains an important strategic partner and continues to play an active role on Nikola's board of directors," Nikola said in a statement to Reuters.

Nikola shares were up 3.4% in after-market trading.

(Reporting by Aakriti Bhalla and Radhika Anilkumar in Bengaluru and Hyunjoo Jin in Seoul; Editing by Arun Koyyur)