* Brent on track for steepest weekly loss in nearly 3 months
* Libya, North Sea supply fall support contract
* Investors focusing on Syria, Fed meeting next week
By James Topham
TOKYO, Sept 13 (Reuters) - Brent crude futures extended gains on Friday towards $113 a barrel on supply concerns, but the contract was still set for its biggest weekly drop in nearly three months as fears of a U.S.-led military attack on Syria recede.
Besides developments relating to the Middle East nation, investors are awaiting a slew of U.S. data slated for release later in the day for more signals on whether the Federal Reserve will begin unwinding its long-standing monetary stimulus this month.
The United States and Russia started talks on Thursday about Moscow's plan for Syria to surrender its chemical weapons, but the U.S. Secretary of State underscored the point that military force may still be needed if diplomacy fails.
Benchmark Brent crude for October, which expires on Friday, was up 4 cents at $112.67 a barrel by 0630 GMT, after gaining $1.13 on Thursday. U.S. crude was 19 cents lower at $108.41.
Brent is now up for three straight sessions but the gains don't seem enough to cover two days of heavy losses in the week that wiped nearly $5 off the European benchmark, and put it on track for a nearly 3 percent weekly drop, its steepest since the week that ended June 21.
"Since concerns on a possible U.S.-led military strike against Syria have eased, market participants are just waiting for the outcome of next week's Fed meeting," said Masaki Suematsu, Energy team manager at Newedge in Tokyo.
"Without new developments on Syria, Brent will likely stay at current levels through early next week while supply concerns in Libya will support prices at $111-111.5," he said.
Libya's state National Oil Corp has declared force majeure on three ports, a company document showed on Thursday, following several weeks of shutdown.
In addition, a processing platform in Norway's Ekofisk crude stream will be partially shut down in the next week for repairs, its operator said on Thursday, which may further delay shipments of the oil that helps set the Brent benchmark.
DATA EYED TO GAUGE FED MOVE
Investors are now awaiting a heap of economic data due out of Washington later in the day, including producer inflation and retail sales figures, which may shed more light on the Federal Reserve's stimulus strategy going forward.
The U.S. central bank is expected to reduce its $85 billion a month bond-buying programme at its two-day policy meeting that ends on Sept 18. But recent weaker-than-expected data intensifies uncertainty about the extent of any reduction.
Asian shares fell on Friday and the dollar held to overnight losses against the yen as investors fretted over not whether but by how much the U.S. Federal Reserve will cut its monthly stimulus at next week's monetary meeting.