Oil prices rose on Tuesday, supported by strong demand in Asia and supply cuts by Abu Dhabi, Kuwait and Qatar as part of production curbs organized by OPEC and other exporters.
But traders said the market was pressured by investors closing financial positions that profited from strong gains the day before.
International Brent crude LCOc1 and U.S. West Texas Intermediate (WTI) CLc1 flirted with negative territory in early European trading. By 1420 GMT, Brent was up 40 cents at $56.09 a barrel, while WTI was up 34 cents $53.17.
Traders said there was significant profit-taking after oil shot to mid-2015 highs earlier this week following a deal reached by the Organization of the Petroleum Exporting Countries and other exporters led by Russia to cut output by almost 1.8 million barrels per day (bpd).
But they added that oil markets were still broadly supported by the arrangement to crimp output.