U.S. stock index futures were little changed on Tuesday following solid gains in the previous session as investors awaited data on home prices and consumer confidence.

Economists expect the Conference Board's Consumer Confidence Index to rise to 57.0 for September, up from August's 54.1, according to a Reuters survey. Despite an improvement, the reading would still be considered far from healthy, suggesting consumers are worried about more economic woes ahead. The data is due at 10 a.m. EDT.

With yesterday's roaring stock market rally on the heels of the deal announcements, investors are now asking, is M&A activity a precursor to a good market or does it follow an already buoyant one? said Peter Boockvar, equity strategist at Miller Tabak & Co in New York.

U.S. stocks rallied on Monday, snapping a three-day losing streak, as a spurt of corporate takeovers in the technology and health-care sectors fueled optimism about share values. The Dow Jones industrial average marked its biggest one-day point and percent gain since August 21, and its 4th highest close this year.

The S&P/Case-Shiller U.S. home price indexes for July are due at 9 a.m. EDT. Economists look for prices in the 20-city index to rise 0.5 percent in July from a 1.4 percent increase in the previous month.

S&P 500 futures fell 2.3 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures lost 5 points and Nasdaq 100 futures fell 6.25 points.

Energy shares are likely to come under pressure, following a drop in crude oil futures. A weak demand outlook expected to be reinforced by weekly inventory data from the United States pushed down crude futures by 0.5 percent.

Walgreen Co shares rose 6.8 percent at $36.40 in premarket trade after the company reported its quarterly results.

Nike Inc , Micron Technology Inc and Jabil Circuit Inc are set to report quarterly results later in the day.

European shares advanced on Tuesday, led by French bank BNP Paribas , which launched a 4.3 billion euro capital increase as it seeks to pay back government aid. (Editing by Padraic Cassidy)