U.S. stocks extended losses on Tuesday, after a bruising selloff a day earlier pushed the S&P 500 to confirm a bear market, as investors braced for an aggressive interest rate hike from the Federal Reserve this week.

The U.S. central bank is expected to raise interest rates by 75 basis points on Wednesday after last week's consumer price inflation data came in much hotter than anticipated.

Wall Street's main indexes have fallen between 16% and 30% this year amid economic uncertainty stoked by supply chain and labor shortages, soaring inflation, the Ukraine war and the impact of aggressive tightening by central banks.

Eight of the 11 major S&P sectors fell, with defensive sectors such as utilities, real estate and healthcare leading the selloff. The energy sector topped the list of gainers, with a 2.1% rise.

Among megacap growth stocks, Amazon fell 0.3%, while Tesla rose 0.4%.

Futures bounced earlier after data showed core producer prices cooled slightly on a year-over-year basis in May.

"Take a look at what the markets look like - interest rates are still a little bit higher, the yield curve is extremely flat, the producer price index came in a little bit better than expected, but not much to really cheer very much about," said Paul Nolte, portfolio manager at Kingsview Investment Management in Chicago.

At 10:36 a.m. ET (1436 GMT), the Dow Jones Industrial Average was down 77.47 points, or 0.25%, at 30,439.27 and the Nasdaq Composite was down 9.69 points, or 0.09%, at 10,799.54.

The benchmark S&P 500 was down 4.81 points, or 0.13%, at 3,744.82, after closing 20% below its all-time closing high hit on Jan. 3 on Monday.

FedEx Corp leaped 12.4% after raising its quarterly dividend by more than 50%, while Oracle shares firmed 9.2% after the firm posted upbeat quarterly results on demand for its cloud products.

Coinbase Global Inc fell 4% after announcing it would slash 18% of its workforce, or about 1,100 jobs, as part of its efforts to cut costs amid volatile market conditions.

Continental Resources Inc jumped 13.9% after the shale producer received an all-cash buyout proposal from its founder Harold Hamm, valuing the company at $25.41 billion.

Declining issues outnumbered advancers for a 1.15-to-1 ratio on the NYSE and a 1.25-to-1 ratio on the Nasdaq.

The S&P index recorded two new 52-week highs and 59 new lows, while the Nasdaq recorded seven new highs and 428 new lows.