US STOCKS-Futures edge up, S&P may have 3rd day of gains
* S&P 500 off more than 2 percent from record close
* Investors continue to watch geopolitical tensions
* ReneSola rallies in premarket after results
* Futures up: Dow 27 pts, S&P 4 pts, Nasdaq 9.25 pts
By Ryan Vlastelica
NEW YORK, Aug 12 (Reuters) - U.S. stock index futures were higher on Tuesday, indicating a potential third straight day of gains as investors continued to bet that tensions in Ukraine would not escalate dramatically.
* Equities have come under pressure because of the problems between Russia and Ukraine, with the S&P 500 at one point down about 4 percent from a record closing high in late July. The benchmark has recovered some of the decline but remained more than 2.5 percent below its record, suggesting traders may see bargains in the market.
* The gain implied by futures came despite ongoing concerns about the region, with Ukraine reporting that Russia had massed 45,000 troops on its border. Russia said a convoy of 280 trucks carrying humanitarian aid had set off for Ukraine, and Western governments warnings against using help as a pretext for an invasion.
* Investors remained concerned about the fallout from any escalation in tensions. In Germany, geopolitical anxiety hit economic sentiment in August, the ZEW think tank said, with investor morale dropping to its lowest since December 2012. Market participants monitored other areas of unrest, including the recent violence in the Gaza Strip and Israel and U.S. air strikes in Iraq. Continuación...