* U.S. crude inventories down for 11th straight week -poll
* Brent reasserts premium over "dislocated" WTI
* Chinese GDP may provide support for prices -analysts
* Coming Up: API inventory report, 2030 GMT
By Alejandro Barbajosa
SINGAPORE, April 13 (Reuters) - Oil fell for a fifth-straight session to about $84 on Tuesday, almost erasing April's gains, as a forecast increase in U.S. crude inventories fanned concern about excess supplies and sluggish demand growth.
U.S. crude stockpiles probably rose for the 11th week in a row last week, a Reuters survey showed ahead of an industry supply report later on Tuesday.
"The market is turning back into consolidation mode," said Stefan Graber, a commodities analyst with Credit Suisse in Singapore.
"There have been fundamental improvements, but the last two weeks have not really shown that much improvement to warrant the strong move higher. There is not a lot of fresh impulse to push prices further."
Front-month West Texas Intermediate (WTI) crude <CLc1>, the U.S. crude benchmark, slid 9 cents to $84.25 a barrel at 0253 GMT, down almost $3 from an 18-month high of $87.09 a week ago.
However ICE Brent crude, the marker for the Atlantic Basin and most of Europe, Africa and Asia, reasserted a premium it gained over WTI on Monday, the first time on a sustained basis this year. Brent rose on Tuesday by 5 cents to $84.82.
The abundance of crude in storage in Cushing, Oklahoma, the pricing point for WTI crude, occasionally triggers a disconnect between the U.S. benchmark and global crude markets better represented by Brent. Traders and analysts label this price divergence as "dislocation."
For a FACTBOX on why WTI is trading below Brent, click: [
]WTI VS BRENT
"On the WTI side we have the inventory situation simply not improving much further and lots of imports into the U.S.," Graber said. "Crude that was outside in floating storage is also coming back onshore."
U.S. crude stockpiles probably gained 1.6 million barrels the week ended April 9, the Reuters poll showed, while supplies of distillates including heating oil and diesel may have added 1 million barrels. Gasoline stocks were anticipated to have slid 700,000 barrels, according to the poll.
The American Petroleum Institute (API) will release U.S. inventory data on Tuesday at 2030 GMT, followed by government statistics from the Energy Information Administration (EIA) on Wednesday at 1400 GMT.
Support for oil prices could come from China's GDP data to be published on Thursday, Credit Suisse's Graber said.
The Chinese economy probably grew 11.5 percent in the first quarter, a Reuters survey showed. That would be the fastest year-on-year rate of growth since the third quarter of 2007. [
]China's March crude oil imports jumped to their second-highest monthly level on record of 4.95 million bpd, up 2.5 percent from February on a per-day basis. [
]"China's oil imports were strong numbers and it confirms that the uptrend in Chinese consumption remains intact," Graber said. "But China alone doesn't seem to enough to keep the rally going." (Editing by Ed Lane)