* Caterpillar warns on faster pace of economic slowdown
* North Sea Buzzard field restart delayed
* U.S. November crude contract expires
* Coming up: API oil data 4:30 p.m. EDT Tuesday (Releads, updates prices, market activity)
By Robert Gibbons
NEW YORK, Oct 22 Oil prices fell on Monday as economic concerns and expected production and pipeline restarts weighed on crude futures and offset support from fears the turmoil in the Middle East may threaten the region's supply.
Brent crude prices fell a fifth straight session and the front-month U.S. November contract expired and went off the board lower as a warning from industrial equipment giant Caterpillar Inc on a global economy slowing faster than expected and data showing Japanese exports tumbled pressured oil.
"I think the outlook from Cat is weighing on the overall demand outlook for oil, helping to push prices lower," said John Kilduff, partner at Again Capital LLC in New York.
TransCanada Corp's expectation that on Monday it will restart its Canada-to-U.S. Keystone crude oil pipeline added pressure on crude oil futures.
Crude prices, especially Brent, were supported as fighting in Lebanon and Gaza and protests in OPEC-exporter Kuwait reinforced concerns about the potential for disruption of Middle East oil supply.
Maintenance-curbed North Sea production, the fear premium associated with Middle East turmoil and recent central bank moves to stimulate sputtering economies have combined to support crude futures, while uncertainty about Europe and slowing growth in China have weighed on oil prices.
Brent December crude fell 70 cents to settle at $109.44 a barrel. The session low of $109.12 was the lowest Brent price since Oct. 4.
The North Sea Buzzard oil field, Britain's largest, is expected to restart on Oct. 25 or 26 after a maintenance shutdown, a trade source said, as many as three days later than previously thought.
Also lending support to Brent, Royal Dutch Shell said it has declared force majeure on exports from Nigeria of Bonny and Forcados crude grades.
Expiring U.S. November crude fell $1.32 to go off the board at $88.73 a barrel, back below $89.97, the 100-day moving average, a technical level monitored by chart-watching analysts and traders.
U.S. December crude fell $1.79 to settle at $88.65.
Brent's premium to U.S. crude CL-LCO1=R remained above $20 a barrel, ending at $20.79 based on December settlements after slipping to $19.08 during the session.
Trading volumes for Brent and U.S. crude lagged their 30-day average by more than 15 percent.
U.S. heating oil fell more than 5.78 cents to settle at $3.0767 a gallon, back below its 50-day moving average of $3.1413. Monday's $3.0735 session low, like Brent crude, was the weakest price since Oct. 4.
U.S. RBOB gasoline also fell nearly 2 percent, dropping 4.88 cents to settle at $2.6475 a gallon.
Crude oil and gasoline inventories in the United States are expected to have risen last week, with total distillate stocks expected to be slightly lower, a Reuters preliminary survey of analysts on Monday showed.
MIDDLE EAST VIOLENCE
At least seven people were killed and dozens wounded in gun battles in Lebanon, violence touched off by the assassination of a senior intelligence officer last week.
The crisis in Lebanon underscores concerns that the 19-month-old uprising against Syria's President Bashar al-Assad is increasingly dragging in neighboring countries. Recent artillery exchanges on the Turkey-Syria border highlighted the danger for the region's oil infrastructure.
"(The tensions) destabilize the whole region and therefore have an impact on oil transportation, especially the oil from northern Iraq, which is transported through pipelines over the crisis region," said Carsten Fritsch, an analyst at Commerzbank in Frankfurt.
Israeli forces killed two Palestinian militants during an incursion in the northern Gaza Strip that touched off clashes with gunmen from the governing Hamas movement.
Police in Kuwait used teargas, stun grenades and baton charges on Sunday to disperse tens of thousands of demonstrators protesting changes to the electoral law which the opposition has called a constitutional coup by the government.
Iran followed the United States on Sunday in denying that the two countries had scheduled direct bilateral negotiations on Iran's controversial nuclear program.
The New York Times, quoting unnamed U.S. administration officials, said on Saturday that U.S. and Iranian officials had an agreement "in principle" to hold one-on-one talks.
(Additional reporting by Alice Baghdjian in London and Manolo Serapio Jr in Singapore; Editing by Marguerita Choy and Bob Burgdorfer)