* Fed, German Court decision, Dutch elections loom
* McDonald's same-store sales climb, but miss estimate
* Indexes up: Dow 0.27 pct, S&P 0.15 pct, Nasdaq 0.03 pct
NEW YORK, Sept 11 (Reuters) - U.S. stocks edged higher on Tuesday as investors stayed in a holding pattern ahead of possible policy action from the Federal Reserve and a key decision by a German court.
Investors may be wary of making big bets on risky assets ahead of a trio of key events later in the week, which could greatly affect markets. The S&P 500 slipped 0.6 percent on Monday as investors locked in gains on a recent rally but remains near levels not seen in over four years.
"There is a lot of stuff out there that people are waiting on right now, a lot of jockeying going on," said Peter Jankovskis, co-chief investment officer at OakBrook Investments LLC in Lisle, Illinois.
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 at the conclusion of 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.
The Dow Jones industrial average gained 35.55 points, or 0.27 percent, to 13,289.84. The Standard & Poor's 500 Index added 2.10 points, or 0.15 percent, to 1,431.18. The Nasdaq Composite Index edged up 0.95 points, or 0.03 percent, to 3,104.98.
McDonald's Corp advanced 0.6 percent to $91.84 after the fast-food restaurant chain reported a 3.7 percent rise in August sales at established restaurants around the world, slightly below expectations of a 3.9 percent increase.
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. FedEx gained 0.4 percent to $88.31 and UPS rose 0.3 percent to $73.27.
Knight Capital Group Inc said it has hired International Business Machines Corp to look into the Aug. 1 trading glitch that cost the trading firm $440 million and forced it to accept a $400 million investment from a group of financial companies to keep it afloat. Knight shares advanced 0.8 percent to $2.69.
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. Zynga shares dropped 2.5 percent to $2.75.
Economic data showed the U.S. trade deficit grew slightly in July, as exports to Germany, France and other European nations shrank and imports from China soared to a new record.