* Bellwether UPS, 3M Company earnings on tap
* Futures up: Dow 33 pts, S&P 4.6 pts, Nasdaq 8.5 pts
* For up-to-the-minute market news see STXNEWS/US
NEW YORK, April 26 (Reuters) - U.S. stock index futures rose on Tuesday ahead of a big day for corporate earnings that includes bellwethers like Amazon.com, Ford, UPS and 3M Company.
* Corporate earnings have been generally strong so far this season with around three-quarters of S&P 500 companies beating analysts' forecasts, helping to push the Dow industrials up to near three-year highs.
* S&P 500 futures added 4.6 points and were above 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 gained 33 points and Nasdaq 100 futures rose 8.50 points.
* United Parcel Service, which as a package delivery company is an economic bellwether, is expected to post a rise in first-quarter operating profit to 83 cents per share from 53 cents a year ago, with revenue increasing to $12.72 billion from $11.73 billion, according to Thomson Reuters.
* Analysts expect Amazon.com Inc to report a first-quarter profit of 61 cents per share, down from 66 cents a year earlier, according to Thomson Reuters.
* Ford is due to report first-quarter results.. Toyota Motor Co may slip behind General Motors and Volkswagen to No. 3 in the automaker production rankings due to Japan's earthquake and tsunami in March.
* In after-hours trading on Monday, shares of Netflix Inc, a leading movie rental service, fell after the market close, when it issued an earnings outlook below expectations.
* Also after the bell, pharmacy benefit manager Express Scripts Inc shares fell after it reported a lower-than-expected quarterly profit.
* Investors are also eyeing the start of a Federal Reserve's two-day policy meeting. Fed Chairman Ben Bernanke is set to hold a press conference after it ends where he will face question about the central bank's stance on monetary policy when it stops its bond buying program in June.
* The U.S. S&P/Case-Shiller Home Price Index for February is due at 9 a.m. (1300GMT) and at 10 a.m. (1400 GMT) is the release of both the U.S. Consumer Confidence for April and the Richmond Fed Manufacturing, Services Indexes for April.
* European shares gained 0.2 percent on Tuesday, with financial stocks among the top performers after UBS client inflows outstripped forecasts.
* U.S. stocks fell on Monday in light volume after Kimberly-Clark lowered its outlook raising investor concerns about higher commodity costs on company profits. ( Editing by W Simon )