* Oil slides under $45 after 6 pct gain overnight
* CFTC investigating United States Oil Fund LP
* Market eyes Q4 U.S. GDP
* NYMEX March RBOB jumps after drop in gasoline stocks
(Updates prices, adds U.S. CFTC investigation, comment)
By Chris Baldwin
LONDON, Feb 27 (Reuters) - Oil fell back on Friday from its three-day bull run, paring around 3 percent in early trade, but otherwise remaining on course to end the month up 5 percent from January, its first monthly gain since June.
OPEC output cuts and a bounce in U.S. demand for gasoline this week pushed oil prices up, and analysts at JP Morgan said tight supply meant "the crude market is finally in balance."
U.S. crude for April delivery <CLc1> was down $1.32 to $43.90 a barrel by 1200 after closing at $45.22 on Thursday, a $2.72 jump. London Brent crude <LCOc1> fell 94 cents to $45.57.
Analyst Oliver Jakob at Petromatrix said Friday's backslide was in large part attributable to the U.S. Commodity Futures Trading Commission's investigation of a crude oil trade earlier this month by the United States Oil Fund LP on the New York Mercantile Exchange. [
]"The CFTC's investigation of US Oil Fund could put pressure on WTI because the positions it had in the market were very large. It was a late development yesterday that figured after the market was already closed," Jakob said.
A steep 3.4 million barrel drawdown in U.S. gasoline stocks announced earlier in the week sparked the rally that has lifted crude prices 13 percent in this week alone. NYMEX March RBOB registered its highest front-month settlement since November.
"With the impact of OPEC production cuts clearly being felt in the markets, we anticipate continued bullishness in the coming week with refinery runs expected to rise sharply, resulting in a crude draw," JP Morgan analysts wrote in their Global Energy Strategy note.
OPEC COMPLIANCE
OPEC has been implementing a 5 percent reduction in its share of global production since September, totalling 4.2 million barrels per day, in order to support falling oil prices.
Oil touched a record high of $147.27 in July, and in the course of six months fell more than $100 to $32.49 in December as the global economy shuddered into a rapid and deep recession.
Signs of recovery have been lacking, with leading industrialised and developing countries releasing economic data regularly that show slumping consumer demand, rising unemployment and frozen credit liquidity.
Geneva-based consultants Petrologistics, which tracks OPEC supply, earlier this week said the Organization of the Petroleum Exporting Countries are on schedule to deliver 89 percent compliance with the production cuts by the end of February.
OPEC members continue to mull the possibility of another output cut at its meeting in March, with the United Arab Emirates cutting allocations for Asian refiners in April.
Venezuela said it wanted OPEC to agree on a new oil output cut, but relatively small member Ecuador said oil prices were stabilising now, brushing off possibility it might urge a cut.
Market players are closely eyeing March heating oil and RBOB gasoline contracts that expire on Friday as well as key economic data, including euro zone January inflation and unemployment figures and U.S. fourth-quarter GDP.
The U.S. GDP figures, due at 1330 GMT, are expected to show the world's largest economy had contracted at a 5.4 percent annual rate, the deepest slide since the first quarter of 1982.
U.S. durable goods orders, an important gauge of business activity, fell for a sixth month to a six-year low in January, suggesting that dried-up credit markets have had a severe impact on industries around the world. (Additional reporting by Angela Moon in Seoul; editing by James Jukwey)