WRAPUP 12-Russian ceasefire and troop pullout must precede any talks, says Ukraine

(Adds Ukrainian president's comments, Ukrainian military report)

* Ukraine dismisses Schroeder comment on 'negotiated solution'

* Schroeder 'voice of Russian royal court', Zelenskiy aide says

* First Ukrainian grain ship in wartime on way to Lebanon

* Russian military active in east, northeast, south -Ukraine

By Natalia Zinets, Umit Bektas and Max Hunder

KYIV/ISTANBUL, Aug 3 (Reuters) - Ukraine on Wednesday dismissed comments by former German Chancellor Gerhard Schroeder that Russia wanted a "negotiated solution" to the war and said any dialogue would be contingent on a Russian ceasefire and withdrawal of its troops.

Schroeder, a friend of Russian President Vladimir Putin and increasingly derided in Germany for his pro-Russia stance, said last month's agreement on grain shipments from Ukraine, aimed at easing a global food crisis, might offer a way forward.

The first grain ship since the war began more than five months ago passed through the Bosphorus Strait on Wednesday en route to Lebanon.

"The good news is that the Kremlin wants a negotiated solution," Schroeder told Stern weekly and broadcasters RTL/ntv, adding he had met Putin in Moscow last week. "A first success is the grain deal, perhaps that can be slowly expanded to a ceasefire."

In response, Ukrainian presidential adviser Mykhailo Podolyak described Schroeder as a "voice of the Russian royal court" and made clear that the grain agreement would not lead to broader negotiations.

"If Moscow wants dialogue, the ball is in its court. First — a cease-fire and withdrawal of troops, then — constructive (dialogue)," Podolyak wrote on Twitter.

In a video address on Wednesday night, Ukrainian President Volodymr Zelenskiy also responded bitterly to the notion of talks with Russia.

"It is simply disgusting when former leaders of major states with European values work for Russia, which is at war against these values," Zelenskiy said.

Tentative attempts at peace talks in March went nowhere.

Russia is engaged in considerable military activity in the east, northeast and south of Ukraine, a statement by the General Staff of the Armed forces said on Wednesday night.

In the northeastern region of Kharkiv, where Ukrainian forces have had success in expelling Russian troops, Russian forces shelled a dozen towns with tank fire and launched air strikes, the statement said.

Shelling was also carried out near the central town of Kramatorsk, which Russian forces hope to capture as they move south, the military said. There was shelling in about eight towns and villages, it said.