By Olesya Astakhova, Dmitry Zhdannikov and Alex Lawler MOSCOW/LONDON (Reuters) - Behind OPEC+'s plan to ramp up oil output and punish over-producing allies, group leaders Saudi Arabia and Russia are pushing a second objective: taking on U.

The group’s previous decision to boost output helped push oil prices down. Now, one option under discussion is a 411,000 barrel-per-day increase in July — three times larger than originally planned, sources told Bloomberg.