STOCKHOLM (Reuters) - Polestar posted a second quarter operating loss on Thursday, a day after the Swedish electric vehicle (EV) maker replaced its CEO amid funding issues and flagging sales.

The luxury car maker has struggled like other EV startups to become profitable, hindered by extensive delays to model launches, missed delivery goals and higher costs.

Polestar said on Wednesday it would replace Thomas Ingenlath, who had been CEO since it was founded in 2017, with Michael Lohscheller, a former boss of Opel and EV startups.

Its second quarter operating loss narrowed slightly to $242.3 million, from a revised $273.6 million a year earlier, as some of its cost reduction actions kicked in.

Meanwhile, its gross margin swung to negative 0.7% in the three-months to June, from 0.1% a year earlier.

Polestar, which is grappling with a challenging demand environment amid a price war ignited by Tesla last year, said its results had been hit by higher discounts and lower volumes.

Revenue for the second quarter fell to $574.9 million, from a revised $693.3 million a year earlier, Polestar said as it stuck to its outlook for a stronger second half of the year.

Unlike some other EV startups, Polestar had strong financial backers in co-founders Volvo Cars and China's Geely. But it suffered a blow earlier in the year when Volvo said it would stop further funding.

Geely has said it intends to continue supporting the group.

Polestar said on Thursday it had in August received an additional $300 in funding through a one-year term loan facility from a bank. Cash and cash equivalents at the end of June were $669 million, compared with $784 million at the end of March.

Punitive import tariffs imposed by the European Union, the United States and Canada on China-made EVs have added further pressure on Polestar, which has until this month only made its cars in China.

However, it started production of its Polestar 3 SUV in the United States earlier this month.

(Reporting by Marie Mannes in Stockholm and Akash Sriram in Bengaluru; Editing by Alexander Smith)