* Russia says it will respond if its Ukraine interests attacked
* U.S. crude oil inventories rise to highest on record -EIA
* Iraq's southern oil exports on track for record in April
* Brent to rebound to $109.66 -technicals (Updates prices)
By Manash Goswami
SINGAPORE, April 24 Brent crude futures rose on Thursday, holding above $109 per barrel for a fifth straight session, as a vow by top oil producer Russia to respond if its interests in Ukraine came under attack stoked supply worries.
Russia accused the United States of being behind the political upheaval in Ukraine, now in its fourth month, which has dragged Moscow's relations with the West to their lowest since the Cold War.
But a rise in oil stockpiles in the United States to a record high kept a lid on oil prices, which have gained 5 percent from a low of $103.95 reached earlier this month.
Brent crude had climbed 28 cents to $109.39 a barrel by 0639 GMT, after settling 16 cents lower. U.S. oil increased 27 cents to $101.71.
"The immediate demand-supply dynamic is negative, but Ukraine is the wildcard that is stopping the market from declining further," said Ric Spooner, chief analyst at CMC Markets. "For the near term, I see markets largely neutral, trading in a range with a downward bias."
NATO says Russia has built up a force of about 40,000 troops in its border with Ukraine. Moscow says some are stationed there permanently, while others have been deployed as a precaution to protect Russia from the instability in Ukraine.
A further escalation could lead to damaging economic sanctions, raising the risk of a disruption in Russian gas supplies on which Europe depends.
While Russia is not key to global oil supplies, it is the top producer and investors are worried a sudden turn in events for the worse could rattle markets.
But keeping a lid on prices was overnight data from the U.S. Energy Information Administration (EIA) that showed crude stocks in the world's top oil consumer rose last week to their highest levels since records began in 1982.
Crude inventories climbed by 3.5 million barrels in the week ending April 18, more than analyst expectations of a 2.3 million-barrel build.
At 397.7 million barrels, they are at their highest since 1982, when the EIA began collecting data. The rise comes even as refinery operating rates increased by 2.2 percentage points to 91 percent of capacity, the data showed.
The gain in stocks despite higher runs highlights U.S. refineries' difficulty in accommodating the rise in local output, analysts at BNP Paribas said in a note.
"With parts of the refinery system continuing to require heavy and sour foreign crudes, insufficient volumes of crude imports are being displaced by indigenous supplies to prevent stocks building," the report said.
The surge in U.S. oil output as a result of a shale boom is mostly of superior quality light crude.
Rising shipments from key Middle Eastern exporter Iraq also capped gains in oil prices. Oil exports from the country's southern terminals are heading for a record high in April, according to loading data and industry sources.
Exports from Iraq's southern terminals have averaged 2.55 million barrels per day (bpd) in the first 23 days of April, according to shipping data tracked by Reuters.
If that is sustained for the rest of April, southern exports this month would top February's level of 2.50 million bpd, the highest since 1979.
An improving supply outlook and simmering geopolitical risk factors will see Brent trading around its 200-day moving average of $108.90 a barrel and the U.S. benchmark around $100.80 in the near-term, Spooner from CMC Markets said. (Editing by Joseph Radford and Himani Sarkar)