By Lisa Pauline Mattackal and Purvi Agarwal

(Reuters) -U.S. stock index futures were subdued on Tuesday as investors took a breather after a rally in the previous session and assessed quarterly results from companies including Bank of America and UnitedHealth.

Dow E-minis were down 34 points, or 0.08%, S&P 500 E-minis were up 1.25 points, or 0.02%, and Nasdaq 100 E-minis were down 0.5 points, or flat.

Health insurer UnitedHealth dropped 3.8% in premarket trading after reporting a surge in medical costs in the third quarter. Johnson & Johnson inched 1.4% higher after lifting its annual profit and sales forecast.

Bank of America was up 1.3% after reporting its quarterly results.

Companies including Goldman Sachs and Citigroup are due to report quarterly results before the bell.

Shares of AI-darling Nvidia fell 1.3% in premarket trading following a record high close on Monday, after a report the U.S. is considering limiting exports of advanced artificial intelligence chips from the company and other U.S. peers to some countries.

Shares of Advanced Micro Devices and Intel were down 1.2% and 0.5%, respectively.

Earnings from major banks including JPMorgan Chase and Wells Fargo kicked off the third-quarter reporting season last week on an upbeat note.

Forty-one S&P 500 companies are scheduled to report results this week, which will help investors gauge the health of the U.S. economy. Large corporates will also need to justify their expensive stock valuations, particularly in the tech sector, where valuations have grown increasingly inflated in the past year.

"As earnings season is set to begin, the tech and communications sectors are expected to post the biggest year-over growth," said Bret Kenwell, U.S. investment analyst at eToro.

"So long as the bullish pillars remain in place for equity markets, we should see the Nasdaq join the S&P 500 and Dow in making new all-time highs."

All three major indexes jumped on Monday, with the S&P 500 and Dow Jones notching record highs for the second consecutive session, as optimism over a strong third-quarter earnings season and a rally in tech stocks lifted equities.

The Dow closed above the 43,000-mark for the first time, while the benchmark S&P 500 is nearing the psychologically significant 6,000 level.

Boeing was down 1% after the planemaker filed a registration statement to sell securities and classes of stock to raise up to $25 billion.

Meanwhile, oil companies lost ground, tracking sharp declines in crude prices as supply concerns eased after a media report said Israel is willing to not strike Iranian oil targets. [O/R]

Exxon Mobil lost 3%, Occidental Petroleum fell 3.2% and Chevron dipped 2.5%.

Traders are pricing in about a 86% probability the Fed will cut rates by 25 basis points in November and a slight chance it will leave rates unchanged, according to CME's FedWatch.

Speeches from Federal Reserve officials Adriana Kugler, Mary Daly and Raphael Bostic are also on deck, while economic data including monthly retail sales figures are due on Thursday.

(Reporting by Lisa Mattackal and Purvi Agarwal in Bengaluru; Editing by Pooja Desai)