CNBC | Oil off highs as rally on output freeze offer fades CNBC Oil prices dipped in and out of negative territory on Tuesday after four of the world's largest producers agreed to freeze output at January levels if other major exporters joined the pact, dashing hopes among the price bulls for an outright cut to supply. Russia and 3 OPEC Members Agree to Freeze Oil Output MarketsBig oil producing countries agree production freeze Potential oil output freeze can't stop oil's slide |