HONG KONG/SHANGHAI (Reuters) -China's Geely is undervaluing its premium electric car unit Zeekr with the $2.2 billion take-private offer it has made, five early investors in Zeekr have written to its board, according to three sources with direct knowledge of the matter.

The investors, including Contemporary Amperex Technology Co Ltd (CATL), Intel Capital and Boyu Capital, who invested in Zeekr's maiden fundraising round, have sent two letters written jointly to the company and a special committee formed to assess the offer, saying that the privatisation price was too low to reflect the fair value of Zeekr, the sources told Reuters.

Geely, one of China's most globally known automakers due to its purchase of foreign marquees such as Volvo and Proton, offered on May 7 to privatise Zeekr, saying it wanted to fully merge Zeekr into Geely Auto.

Geely Auto owns about two-thirds of Zeekr. Both companies sit under the umbrella of their unlisted parent, Geely Holding. Geely founder and chairman Eric Li also chairs the Zeekr board.

The move surprised the market and the auto industry, given how it came just a year after it took the EV brand public in the United States.

It has also raised questions on the prospects of two other Geely units preparing for Hong Kong listings, including ride-hailing firm CaoCao Inc, and raised questions over whether Geely might delist its other U.S.-listed units such as Polestar.

The other two investors who wrote the letters were Bilibili and Cathay Fortune Corp.

A spokesperson for Geely said that talks with Zeekr's special committee were ongoing.

Zeekr, CATL, Intel Capital, Boyu Capital, Cathay Fortune did not respond to requests for comment. Bilibili declined to comment.

The offer is non-binding according to Geely Auto's filing. A binding commitment will only arise upon the execution of definitive agreements, subject to the terms and conditions, it said.

IMPROVING THE STRATEGIC FOCUS

Li has pivoted Geely away from its history of aggressive acquisitions to streamlining operations and cutting costs amid a brutal price war in China's auto market, the world's biggest.

He launched last year a campaign to improve the group's strategic focus and eliminate internal competition, which has so far involved it restructuring its brands into two units and merging some teams that were working on digital cockpit technology.

Zeekr is now viewed as Geely's best asset - sales of the brand reached 41,403 units in the first quarter of this year with six models, increasing 25% from a year ago and outselling BYD's premium brand Denza.