BlackRock's long-dated Treasury ETF set for worst week in 13 months

NEW YORK, July 15 (Reuters) - A BlackRock (Sao Paolo: BLAK34.SA - news) exchange-traded fund that tracks long-dated U.S (Other OTC: UBGXF - news) . Treasuries was poised for its biggest weekly loss in 13 months as a rebound in stock markets worldwide stoked a sharp sell-off in U.S. government debt.

BlackRock's iShares 20-Plus Year Treasury bond ETF has fallen 3.5 percent on the week, which would be its steepest single weekly decline since a 4.2 percent drop in the week of June 5, 2015.

The exchange-traded fund had $8.8 billion in assets at the end of June, Reuters data showed.

At 2:26 p.m. (1826 GMT), the ETF was down 0.9 percent on the day at $138.30 a share.

A week ago, the fund hit an all-time high of $143.62 as investors piled into long-dated U.S. government bonds in a scramble for stable investments, driving their yields to historic lows. Investors had been worried about the global economy following Britain's surprise vote to leave the European Union on June 23.

Their anxiety abated in response to a robust June U.S. jobs report and another possible round of stimulus in Japan to help its sluggish economy.

The 30-year Treasury yield, which moves inversely to its price, hit a two-week high of 2.310 percent on Friday after hitting a record low of 2.089 percent on Monday.

The Standard & Poor's 500 index posted a series of record highs this week before disappointing bank earnings cut into its rally on Friday.

Despite a brutal week, BlackRock's 20-plus year Treasury ETF has produced a total return of 16.03 percent this year, beating a 6.89 percent year-to-date return on the Standard & Poor's 500 index (Reporting by Richard Leong; Editing by Tom Brown)