* Futures down: Dow 68 pts, S&P 8 pts, Nasdaq 16 pts
NEW YORK, Oct 7 (Reuters) - U.S. stock index futures were falling on Tuesday, pressured by a second straight day of weak data out of Germany, the euro zone's largest economy.
* German industrial output figures for August plunged 4 percent, the biggest fall in 5-1/2 years, a day after industrial orders saw their biggest monthly drop since 2009.
* Major U.S. equity indexes fell on Monday with traders wary about the effect of both a strong dollar and economic weakness in Europe on corporate results.
* U.S.-traded shares of Rio Tinto were down 1.7 percent premarket a day after gaining more than 9 percent, after the iron ore producer said it rejected a merger approach from smaller rival Glencore Plc back in August.
* Shares of Agco Corp were falling 10.8 percent after the company revised its earnings outlook lower, citing lower sales and lower production.
Futures snapshot at 7:27 (1127 GMT):
* S&P 500 e-minis were falling 7.75 points, or 0.4 percent, with 154,698 contracts changing hands.
* Nasdaq 100 e-minis were down 16 points, or 0.4 percent, in volume of 26,045 contracts.
* Dow e-minis were down 68 points, or 0.4 percent, with 26,069 contracts changing hands (Reporting by Rodrigo Campos; Editing by Chizu Nomiyama)