TREASURIES-Long bonds gain as investors grab for higher yields

(Adds quote, updates prices)

* Yield curve flattens as demand for yield boosts long-dated

debt

* ECB meeting in focus for Thursday, QE expected

* Slow global growth prospects adds bid for bonds

By Karen Brettell

NEW YORK, Jan 20 (Reuters) - U.S. Treasury prices gained on

Tuesday with 30-year bonds leading the rally, as investors bet

the European Central Bank will launch new quantitative easing

this week, keeping longer-dated debt in demand as investors hunt

for higher yields.

The ECB meeting on Thursday is this week's main focus, when

many expect the central bank will announce purchases of

government bonds in a bid to fight off deflation and kickstart

growth.

"If you are looking for ECB to not disappoint on Thursday,

the predominant view is that you still won't have enough

long-dated assets, and I think that is driving the flattener

today," said Gennadiy Goldberg, an interest rate strategist at

TD Securities in New York.

The yield curve between five-year notes and 30-year bonds

flattened to 111 basis points, after steepening

to 121 basis points on Friday.

Record (LSE: REC.L - news) low yields on German and other European sovereign

debt have contributed to demand for U.S. Treasuries, which pay

far higher yields, even as the Federal Reserve is expected to

increase interest rates this year as the U.S. economy improves.

The surprise move by the Swiss central bank last week to

dump a three-year old currency cap against the euro has also

increased bets that the European single currency will continue

to decline, making dollar-denominated assets such as Treasuries

relatively attractive.

"People are expecting euro currency to cheapen up over time

and if that is the case, I would imagine that there are still a

lot of people that will be interested in owning dollar product,"

said Tom Tucci, head of Treasuries trading at CIBC in New York.

Benchmark 10-year notes were last up 11/32 in

price to yield 1.80 percent, just above almost two-year lows of

1.70 percent reached on Friday.

Thirty-year bonds gained 1-7/32 in price to

yield 2.40 percent, after falling to record lows of 2.35 percent

last Thursday.

The outlook for weak global economic growth also added a bid

for bonds on Tuesday.

The International Monetary Fund lowered its forecast for

global economic growth in 2015, and called on Tuesday for

governments and central banks to pursue accommodative monetary

policies and structural reforms to support growth.

China's economy grew at its slowest pace in 24 years in 2014

as property prices cooled and companies and local governments

struggled under heavy debt burdens, though many investors were

relived growth wasn't as bad as they had feared.

(Editing by Meredith Mazzilli and Chris Reese)