TREASURIES-Treasuries up as ISM manufacturing index awaited

* Sept ISM manufacturing index forecast at 49.7

* Focus on potential weakness in ISM shipments index

* Concern over time Spain is taking to request bailout

(Updates comment, prices) By Ellen Freilich

NEW YORK, Oct 1 (Reuters) - U.S. Treasuries prices rose on Monday as expectations that a U.S. manufacturing report would be subdued and concern about the time Spain is taking to request a bailout fed the bid for safe-haven U.S. debt.

The influential Institute for Supply Management manufacturing index due at 10 a.m. EDT (1400 GMT) is expected to be bullish for Treasuries with a reading of 49.7 forecast for September, little changed from the August reading of 49.6.

Readings below 50 point to contraction in manufacturing.

"The ISM survey will be the main event today, as markets look for some definitive indication on the next big move in manufacturing activity," said Pierre Ellis, senior economist at Decision Economics in New York.

To that end, the market will focus on the new orders component of the report "which has floated two to three points below the zero-growth 50 level ever since June, when it dropped 12.3 points," he said.

"Any significant further worsening in orders would be read as a serious negative for the outlook ... (and) would accelerate speculation that the FOMC will step up the QE3 pace unless the situation improves very quickly," Ellis said, referring to the Federal Open Market Committee's third phase of quantitative, or unconventional, monetary easing.

The government's August construction spending report, also due at 10 a.m. EDT (1400 GMT), is expected to show a 0.5 percent rise after a 0.9 percent drop in July. These data "seldom cause excitement" in the markets, Ellis observed.

In early dealings, the benchmark 10-year Treasury note was up 2/32, leaving its yield at 1.63 percent

, midway between a low of 1.38 percent set in late July and a high of 1.89 percent reached in mid-September.

The final reading for the Markit U.S. manufacturing sector PMI for September of 51.1 had no discernible impact on Treasuries prices.

(Editing by)

(( 646 223 6309)(Reuters Messaging:

((-------------- MARKET SNAPSHOT AT 0901 EDT (1301 GMT) ---------------------

Change vs Current Nyk yield Three-month bills 0.095 ( unch ) 0.096 6-month bills 0.135 ( unch ) 0.137 Two-year note 100-01/32 (+01/32) 0.238 Five-year note 99-31/32 ( unch ) 0.627 10-year note 99-20/32 (+02/32) 1.630 30-year bond 98-16/32 (+02/32) 2.824 ))