US stocks have slashed steep early losses in the last hour of trade to end moderately lower, amid short covering and hopes that EU leaders would agree measures to stem the eurozone crisis.

Falls in tech stocks ruled the day as the US Supreme Court’s ruling in favour of the Obama administration’s controversial health care law had little overall effect on trade.

The Dow Jones Industrial Average on Thursday closed down 24.75 points (0.20 per cent) at 12,602.26, after having been off by more that 170 points during the session.

The S&P 500 index lost 2.81 (0.21 per cent) to 1329.04, while the tech-rich Nasdaq lost 25.83 (0.90 per cent) to 2849.49.

The Dow was more than one per cent lower earlier, amid worries of deep rifts in the EU leaders’ crisis summit in Brussels.

The late surge was likely tied to investor moves related to the end of the quarter on Friday, said Peter Cardillo of Rockwell Global Capital.

“Tomorrow is the last day of the quarter and you might have some short covering ahead of that,” he said.

The healthcare sector ended down 0.31 per cent, as the court’s ruling against major Republican-backed challenges to the White House’s landmark health care reforms had a mixed effect on different components of the giant industry.

“The law is not bullish for corporate America, (bringing) higher healthcare costs,” said Mace Blicksilver of Marblehead Asset Management.

However, he added, “It’s very beneficial for hospitals, less beneficial for those managed care companies.”

Hospital shares rose 1.7 per cent, insurers were up 0.7 per cent, drug manufacturer and drug delivery/pharmacy stocks were down 0.1 per cent, and healthcare plans were virtually unchanged following the court’s decision.

Drugmakers were mixed: Johnson & Johnson gained 0.2 per cent, Pfizer was 0.4 per cent off, and Merck gained 0.4 per cent.

JPMorgan Chase shares fell 2.5 per cent on a report that its losses on a mismanaged derivatives trading operation could hit $9 billion.

News Corp shares sank 1.4 per cent after it confirmed it would split into two separate businesses.

On the Nasdaq, eBay fell 3.6 per cent, Seagate 5.2 per cent, Intel 1.5 per cent and Facebook 2.7 per cent.

Bond prices pushed higher. The yield on the 10-year Treasury fell to 1.58 per cent from 1.62 per cent Wednesday, while the 30-year yield fell to 2.67 per cent from 2.69 per cent.

Bond prices and yields move in opposite directions.