Oil Climbs From Multi-Month Lows After China Equity Gains

At the close, Brent was up 47 cents, or 1 percent, at $49.99 a barrel. It hit a six-month low on Monday, coming within cents of its 2015 bottom of $49.19.

U.S. crude settled up 57 cents, or 1.3 percent, at $45.74. It plumbed a four-month bottom of $45.17 the previous session, about $3 from the year low.

"The bigger picture still points to a retest of 2015 lows," Matt Smith, director of commodity research at New York energy database ClipperData, said, adding that next week's "triumvirate of monthly oil-specific reports" could be the catalyst.

Crude has come under pressure from signs of too much supply and too little demand.

OPEC, which groups Saudi Arabia and other major crude producers, has been producing about 1.7 million bpd in surplus since deciding in November to favor market share over price defense.

The ensuing glut knocked Brent down 18 percent in July. U.S. crude tumbled even more, 21 percent, for its biggest monthly decline since the 2008 financial crisis.

New lows for 2015 look "inevitable given current ample market supply and intensifying bearish market sentiment towards prices," BMI Research said in a note.