* Fed, German Court decision, Dutch elections loom
* FedEx, UPS to provide services in some Chinese cities
* Futures up: Dow 45 pts, S&P 5.6 pts, Nasdaq 3.5 pts
By Chuck Mikolajczak
NEW YORK, Sept 11 (Reuters) - U.S. stock index futures edged up on Tuesday as investors exercised caution ahead of possible policy action from the Federal Reserve and a key decision by a German court.
Investors may be reluctant to make bets on risky assets ahead of a trio of key events later in the week, which could greatly impact markets. On Monday, investors locked in gains on a recent rally, with the S&P 500 down 0.6 percent.
Germany's Constitutional Court on Wednesday is expected to approve the European Stability Mechanism -- the euro zone's new bailout fund -- but legal experts believe it will impose tough conditions limiting Berlin's flexibility on future rescues.
Investors also were awaiting a decision by the Federal Reserve on any additional stimulus measures when the central bank announces its policy decision after a two-day meeting on Thursday. Equities have rallied on expectations for fresh stimulus measures from central banks, with economists forecasting a 60 percent chance the Fed will announce another round of quantitative easing.
Another event which could cause turbulence in markets is a Dutch general election on Wednesday, with voters divided between bailouts for troubled euro zone economies and austerity measures locally.
"It is one of those 'wait and see days' days where we have a week full of catalysts that basically start tomorrow so with that, this market probably sees a day full of sideways action," said Art Hogan, managing director of Lazard Capital Markets in New York.
"Sometimes it is what it is and it's the calm before the storm."
S&P 500 futures rose 5.6 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 45 points, and Nasdaq 100 futures added 3.5 points.
Package delivery companies FedEx Corp and United Parcel Service Inc have received approval to provide express-package services in some cities of China on their own, the country's State Postal Bureau (SPB) said on its website last week.
Sales of the new iPhone could add between a quarter and a half percentage point to fourth-quarter annualized growth in the United States, J.P. Morgan's chief economist Michael Feroli said in a note to clients on Monday.
Zynga Inc's chief marketing officer resigned on Monday, becoming the latest senior executive to depart the struggling social games company behind popular Facebook Inc games such as Farmville.
Economic data on tap includes U.S. international trade numbers, to be released at 8:30 a.m. (1230 GMT). Economists in a Reuters poll expect a trade deficit of $44.0 billion in July versus a deficit of $42.9 billion in June.
The rally in European equities stuttered for a second day in sight of 13-month highs, with investors concerned about the strings that Germany may attach to the euro zone bailout fund and the chance the United States may not deliver widely awaited stimulus.
Asian shares fell as investors repositioned before the German Constitutional Court ruling on the euro zone's bailout funds and a U.S. Federal Reserve meeting that may yield widely expected monetary easing.