France, Nov. 4 -- The prospect of tighter regulation weighed on shares in AI heavyweights such as Elon Musk's SpaceX before the opening of US markets, after falls for major Asian chipmakers including South Korea's Samsung.

The campaign was marked by growing concern about the environmental impact of the data centres springing up across the US. It ended in a stinging rebuke for President Donald Trump's Republican Party.

Trump is an enthusiastic supporter of light-touch regulation for what he calls "super intelligence".

Microsoft to open four data centres in France

Democrats won key Republican strongholds such as Texas, where both the Senate seat and the governorship went to candidates who back tighter regulation of data centres.

"We ne...