FRANKFURT, Oct 25 (Reuters) - Germany, battling to compensate for loss of Russian gas, could double the share of domestic gas usage if the right legal framework was in place to back up such moves, oil and gas producer Wintershall Dea's chief executive said in a media call on Tuesday.

"Germany is producing about 5% of domestic demand at home and could bring it up to close to 10% only using conventional fields," CEO Mario Mehren said after presenting third quarter results.

"We could start tomorrow but we need political support from the government and relevant authorities." (Reporting by Vera Eckert, editing by Rachel More)