April 1 (Reuters) - U.S. stock indexes bounced off session lows on Tuesday, helped by gains in heavyweight technology stocks and Tesla, while investors awaited details on fresh U.S. tariffs set to be announced on Wednesday.

Financial markets had been volatile in recent weeks as investors assessed the economic fallout of U.S. President Donald Trump's extensive tariff plans, which have sparked worries about a U.S. economic slowdown and higher inflation.

The benchmark S&P 500 closed the first quarter 4.6% lower, marking its most dismal three-month stretch since July 2022.

"The market is pricing in the worst case scenario, and if we aren't yet at wash out levels then we're pretty close," said Gina Bolvin, president of Bolvin Wealth Management Group at Boston. "I wouldn't be a seller into this correction."

White House aides have drafted plans for 20% tariffs on most goods imported to the United States, the Washington Post reported on Tuesday. Trump is due to unveil his tariff plan at 4 p.m. ET at an event in the Rose Garden on Wednesday.

After falling about 1% earlier, the S&P 500 gained ground in the session, with beaten-down technology shares taking the lead.

Microsoft rose 1.6% and Tesla jumped 5.9%.

Other big tech stocks, such as Amazon.com, Nvidia and Meta Platforms, rose about 1% each.

Investors appeared to look past data that showed U.S. manufacturing contracted in March after expanding two consecutive months, while a measure of inflation at the factory gate jumped to the highest level in nearly three years amid rising anxiety over tariffs on imported goods.

A labor report also showed job openings fell to 7.568 million in February.

At 11:51 a.m. ET, the Dow Jones Industrial Average rose 48.75 points, or 0.13%, to 42,057.16. The S&P 500 rose 21.65 points, or 0.40%, to 5,634.07 and the Nasdaq Composite rose 146.62 points, or 0.87%, to 17,450.19.

Trump has already implemented levies on imported aluminum and steel, along with increased tariffs on goods from China. Higher duties on cars will take effect on Thursday.

Goldman Sachs on Monday raised the probability of a U.S. recession to 35% from 20% and said it expects more U.S. interest rate cuts this year.

Among single stocks, Johnson & Johnson fell 5.2%, dragging the broader healthcare sector to the bottom. A U.S. bankruptcy judge rejected the company's $10 billion proposal to end tens of thousands of lawsuits alleging its baby powder and other talc products cause ovarian cancer.

Conservative news outlet Newsmax jumped 62%, following a more than 700% surge in its NYSE debut on Monday.

PVH Corp climbed 17% after the apparel maker's annual earnings forecast beat analysts' estimates.

Tesla's shares gained 6.2% ahead of its first-quarter vehicle deliveries report on Wednesday. Its shares fell about 36% in the three months to March 31.

Advancing issues outnumbered declining ones by a 2.3-to-1 ratio on the NYSE and a 1.5-to-1 ratio on the Nasdaq.

The S&P 500 posted seven new 52-week highs and five new lows, while the Nasdaq Composite recorded 20 new highs and 316 new lows.