NEW YORK (Reuters) - Wall Street’s major indexes rose on Thursday as reports that the United States and the European Union may agree to withdraw auto tariffs fostered optimism on international trade relations among investors.

German Chancellor Angela Merkel said she would back lowering EU tariffs on U.S. car imports. An industry source told Reuters that the U.S. ambassador to Germany, Richard Grenell, had mentioned to German auto executives that U.S. President Donald Trump could abandon threatened tariffs on imported European cars if in return the European Union scrapped duties on U.S. cars.

U.S. stocks added to gains in the last hour of trading after having slightly pared gains upon the release of minutes from the Federal Open Market Committee’s June meeting.

The minutes reflected confidence among the Federal Reserve’s policymakers in the strength of the U.S. economy and its plans for future interest-rate hikes. In the June meeting, the Fed increased rates for the second time this year, and it has signaled that additional increases are likely.

Technology stocks led gains on the S&P 500, with shares of several chipmakers rising. The Philadelphia semiconductor index rose 2.7 percent.

“The fact that EU and U.S. officials are discussing proposals to eliminate certain tariffs on auto imports, that’s helping sentiment today and calming fears of an escalating trade war,” said Ryan Larson, head of U.S. equity trading at RBC Global Asset Management in Chicago.

Still, the Trump administration’s tariffs on $34 billion worth of Chinese imports are due to go into effect at 0401 GMT on Friday. Beijing said it would respond immediately and in equal measure on U.S. goods ranging from cars to soybeans.

FILE PHOTO: Traders work on the floor of the New York Stock Exchange (NYSE) in New York, U.S., June 28, 2018. REUTERS/Brendan McDermid

There was no evidence of any last-minute negotiations between U.S. and Chinese officials, business sources in Washington and Beijing said.

Investors, however, suggested that Friday’s impending tariffs had already been priced into stocks.

“There’s a lot of uncertainty, but the markets have reacted fairly calmly and rationally,” said Oliver Pursche, chief market strategist at Bruderman Asset Management in New York. “There’s been a lot of rhetoric but not a lot of actual action in terms of a trade war.”

The Dow Jones Industrial Average rose 181.92 points, or 0.75 percent, to 24,356.74, the S&P 500 gained 23.39 points, or 0.86 percent, to 2,736.61 and the Nasdaq Composite added 83.75 points, or 1.12 percent, to 7,586.43.

To view a graphic on The US-China tariff war and the S&P 500, click: reut.rs/2tV7kTm

Shares of chipmaker Qorvo Inc rose 5.7 percent after KeyBanc, citing strong demand for smartphones in China and stabilizing iPhone sales, upgraded the company’s stock to “overweight.” Chipmaker Micron Technology Inc’s shares rose 2.6 percent after the company forecast only a small hit from a temporary ban on some sales in China.

Earlier on Thursday, the ADP National Employment Report showed private employers added 177,000 jobs in June, below Reuters’ consensus of an increase of 190,000. That comes ahead of the more comprehensive non-farm payrolls report on Friday.

Advancing issues outnumbered declining ones on the NYSE by a 2.79-to-1 ratio; on Nasdaq, a 2.40-to-1 ratio favored advancers.

The S&P 500 posted six new 52-week highs and three new lows; the Nasdaq Composite recorded 96 new highs and 36 new lows.

Volume on U.S. exchanges was 5.76 billion shares, compared to the 7.07 billion average over the last 20 trading days.