TREASURIES-Bond yields fall on weak European data, U.S. strikes

* Weak European data boosts demand for U.S. yields

* U.S. and Arab allies bomb Syria for first time

* U.S. sells $29 bln in two-year notes

* U.S. flash PMI unchanged from August reading (Updates prices, adds comments)

By Sam Forgione

NEW YORK, Sept 23 (Reuters) - U.S. benchmark and long-dated Treasuries yields fell on Tuesday to their lowest since Sept. 11 after weak European economic data raised concerns about global growth and U.S. strikes in Syria spurred safe-haven bids.

European data showed a contraction in French business activity and slower growth in German manufacturing this month. Analysts said concerns of slowing global economic growth pushed European bond yields lower and drove demand for higher-yielding U.S. Treasuries.

"The European economy is sputtering again," said Robbert van Batenburg, director of market strategy at Newedge USA LLC in New York.

German 10-year bund yields fell to 1.01 percent, their lowest since Sept. 11.

U.S. and Arab warplanes bombed Syria, triggering concerns about the extent of U.S. involvement and the impact on oil prices. The strikes against Islamic State targets drove safe-haven bids on concerns the conflict could intensify.

The U.S. Treasury sold $29 billion in two-year notes to solid demand. Overall bidding for the two-year supply, as measured by the bid-to-cover ratio, was at 3.56, marking the highest level since February.

"The uncertainty of the Fed is out of the way, so I think people feel comfortable going back in," said Chris McReynolds, head of U.S. Treasury Trading at Barclays (LSE: BARC.L - news) in New York, on the solid demand for two-year notes in the wake of the Fed's last policy meeting on Sept. 17.

Traders maintained the view that low inflation and struggling U.S. jobs growth would prevent the Fed from raising rates as quickly as their latest rate projections suggest. That view of a more dovish Fed helped Treasuries yields edge lower.

Federal Reserve Bank of Minneapolis President Narayana Kocherlakota underpinned that dovish outlook on Tuesday and said the Fed can keep stimulating the U.S. economy because inflation is posing little threat.

"The Fed rate projections are completely ludicrous," van Batenburg of Newedge said.

Benchmark U.S. 10-year Treasury notes were last up 8/32 in price to yield 2.54 percent from 2.57 percent late on Monday. Benchmark yields touched 2.533 percent, their lowest since Sept. 11.

U.S. 30-year Treasuries were last up 21/32 to yield 3.25 percent from 3.29 percent late Monday. U.S. 30-year yields touched 3.246 percent, also their lowest since Sept. 11.

Manufacturing data had little impact on Treasuries.

Financial data firm Markit (Stuttgart: A1139A - news) said its preliminary or "flash" U.S. Manufacturing Purchasing Managers Index was unchanged from August's reading of 57.9, the highest since April 2010. Economists polled by Reuters expected it to edge up to 58.

On Wall Street, U.S. stocks fell on the signs of slowing global growth. The S&P 500 was last down 0.34 percent. (Editing by W Simon)