ECB to release documents to defuse German court challenge

The European Central Bank agreed to give vital documents to German authorities to prove the proportionality of ECB policies, two sources said, in a step to defuse a challenge threatening to undermine its powers to keep the euro zone together.Germany's Constitutional Court ruled in May that the ECB overstepped its mandate with over 2 trillion euros of government bond purchases, ordering the Bundesbank to quit the scheme unless the ECB can prove proportionality within three months.