(Adds industry background, analyst comment, details of survey)
By Richard Leong
Aug 29 (Reuters) - More investors are warming to the idea of owning a U.S. Treasury bond that matures beyond 30 years, but most still prefer the U.S. Treasury Department to roll out a 20-year security over an ultra-long issue, a J.P. Morgan survey showed on Thursday.
Thirty-nine percent of the nearly 130 respondents said they would buy an ultra-long Treasury bond. This was more than the 19% who said they would do so two years ago, according to the survey. The respondents include banks, asset managers and hedge funds.
Half of those surveyed said they prefer a 20-year Treasury security in the latest survey. That figure was significantly lower than 73% two years earlier.
The rest of investors said they favor an ultra-long zero-coupon security, slightly higher than in the prior survey.
Earlier this month, the U.S. Treasury Department asked for updates from market participants about the possibility of selling ultra-long bonds.
U.S. Treasury Secretary Steven Mnuchin told Bloomberg News on Wednesday the possibility of issuing ultra-long U.S. bonds is "under very serious consideration" by the Trump administration.
On Wednesday, the yields on U.S. 30-year Treasury bonds, the government's longest-dated debt security, fell to record lows on a global scramble for bonds due to fears about a recession and U.S.-China trade tensions.
The yields on the 30-year, or "long," bond, are now lower than the Fed's target range on policy rates, which are currently at 2.00%-2.25%.
For some fund managers, the idea of the government locking in long-term rates at all-time lows is appealing.
Britain, Japan and a number of European countries issue sovereign bonds that mature in 50 years.
"It makes total sense. For the government, it should issue as much as it can," said Carl Kaufman, managing director of fixed income at Osterweis Capital Management in San Francisco.
Wall Street on the other hand remained cautious about the federal government borrowing beyond 30 years from the bond market.
"Overall, we do not see a strong case to issue an ultra-long maturity, for a number of reasons," J.P. Morgan strategists said in a note on the results of the survey.
Investors in the survey said an ultra bond would likely cannibalize demand for existing long-dated Treasuries, the strategists said.
Demand from private pension funds will likely dwindle, while foreign appetite at 30-year bond auctions has waned in recent years, they noted.
Moreover, introduction of an ultra-long bond does not fit with the Treasury's current objectives because it would raise its borrowing costs "without meaningfully reducing risk," they said. (Reporting by Richard Leong in New York Editing by Matthew Lewis)