By Georgi Kantchev And Nicole Friedman 

NEW YORK--Oil prices ticked lower Tuesday, halting a rally that many analysts say might not be sustainable.

U.S. oil prices have risen close to 30% since a low in March on expectations the oversupplied market will come into balance later in the year. But analysts have warned that although U.S. oil production could stop growing or even fall in the coming months, other major producers are still pumping at a fast pace, exacerbating the global glut.

Light, sweet crude for May delivery recently traded down 21 cents, or 0.4%, to $56.17 a barrel on the New York Mercantile Exchange. The May contract expires at settlement Tuesday. The more-actively traded June contract fell 45 cents, or 0.8%, to $57.43 a barrel.

Brent, the global benchmark, recently fell 59 cents, or 0.9%, to $62.86 a barrel on ICE Futures Europe.

Oil prices have risen in nine of the last 11 trading sessions but are still off more than 40% from last summer's peak.

"While the shift in sentiment isn't necessarily flawed, the swing to the extreme is overdone," said analysts at London-based consultancy Energy Aspects.

Market participants are bracing for the latest U.S. supply data, due Wednesday. The U.S. Energy Information Administration has reported a drop in weekly production in two of the past three reports, and many market watchers are waiting to see if the trend will continue.

"The weekly numbers on production are an estimated output of a model, rather than being observed data," and therefore are unreliable, said Citigroup in a note. "The risk to the market is now that the rally has come too soon for supply to get meaningfully curtailed," which could set prices up to drop again in the second half of the year, the bank said.

The American Petroleum Institute, an industry group, will release its own U.S. inventory data later Tuesday.

Market observers are also starting to speculate whether the Organization of the Petroleum Exporting Countries will make any changes to its stance of keeping its oil-production quota at 30 million barrels a day at its next meeting in June.

Key OPEC members like Saudi Arabia and Iraq have been increasing their production in recent months, leading the organization to overshoot its own target output.

According to J.P. Morgan, oil prices have stabilized and the medium-term outlook has improved substantially since the beginning of the year.

But the bank cautions that "near-term price volatility could persist as supply from the Middle East is expected to remain high, with Saudi Arabia and Iraqi production on the rise."

J.P. Morgan sees Brent averaging $59 a barrel this year and rising to $62 a barrel in 2016. U.S. oil prices will average $52 a barrel this year and rise to $54 in the next, the bank says.

Gasoline futures recently fell 1.2% to $1.9086 a gallon. Diesel futures slipped 0.2% to $1.8733 a gallon.

Write to Georgi Kantchev at georgi.kantchev@wsj.com and Nicole Friedman at nicole.friedman@wsj.com

Access Investor Kit for Citigroup, Inc.

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US1729674242

Citigroup (NYSE:C)
Historical Stock Chart
From Mar 2024 to Apr 2024 Click Here for more Citigroup Charts.
Citigroup (NYSE:C)
Historical Stock Chart
From Apr 2023 to Apr 2024 Click Here for more Citigroup Charts.