Yes, he may have! A Soviet agent, whose name is in the source that I will cite (and when I get home I'll find his name) was sent to contact the Bulgarian ambassador by Lavrentii Beria. Beria told him to pass on three questions:
Why the Germans had broken the Molotov-Ribbentrop pact.
What would be necessary to end the war.
Would Hitler be satisfied with Ukraine, Belarus, Poland and the Baltics, a second "Brest-Litovsk".
Beria claimed that the Soviet leadership was doing this to buy time. The ambassador, however, never passed on the offer to the Germans, as he said to the Soviet agent "Even if you are pushed back to the Urals, you will still win".
The book does say that this information comes from a semi-reliable memoir of the Soviet agent, but it's the closest thing we can find to the Soviets making - even if not honestly - a peace overture.
Source: The Court of the Red Tsar, by Simon Sebag-Montefiore.