PREVIEW-Medvedev goes to Germany to defend key projects

* Will defend Magna/Sberbank deal on Opel, aide says

* Will seek more support for Nord Stream pipeline

* Germany-Russia trade more than halves in Q1

* Key goal to uphold economic ties

By Oleg Shchedrov

MOSCOW, July 15 (Reuters) - President Dmitry Medvedev will defend a Russia-backed deal to buy German car maker Opel and seek more support for the Nord Stream gas pipeline project when he visits Munich on Thursday, a top Kremlin aide said.

Sergei Prikhodko, the Kremlin's chief foreign policy aide, told reporters that top-level intergovernment consultations in southern Germany would be dominated by efforts to keep afloat bilateral trade and economic ties hit by the global crisis.

Prikhodko said trade between Russia and Germany, its leading business partner, more than halved in the first quarter of 2009 compared with the same period last year. He gave no precise figure.