* Concerns about large Portugal bank spur bids for bonds
* Longer-dated U.S. yields fall to 5-week lows
* U.S. to auction $13 billion of 30-year bonds
* Fed to buy $450-$600 million in TIPS (Updates market action, adds quotes)
By Richard Leong
NEW YORK, July 10 (Reuters) - U.S. Treasuries prices rose on Thursday, with benchmark yields falling to their lowest in five weeks as investors scrambled for low-risk bonds on worries that problems around Portugal's biggest listed bank may rekindle the region's financial woes.
The bond market was also on track to stretch its winning streak to four sessions following the minutes on the Federal Reserve's June 17-18 policy meeting released on Wednesday, which suggested the central bank is unlikely to raise policy rates until the second half of 2015.
Demand for Treasuries has been underpinned by the global drop in stock prices, weak overseas economic data and intensified fighting between militants in Gaza and the Israeli military.
Growing safe-haven appetite may boost bidding at the $13 billion auction of 30-year Treasuries at 1 p.m. (1700 GMT), the last leg of this week's $61 billion in fixed-rate government debt supply, traders said.
"There's a lot of reasons to find comfort in Treasuries right now," said Mike Lorizio, head of Treasuries trading at John Hancock Asset Management in Boston.
Benchmark 10-year notes were up 10/32 in price with a yield of 2.509 percent, down nearly 4 basis points from Wednesday, while prices on 30-year bonds rose 13/32, yielding 3.338 percent, down 2 basis points on the day.
Longer-dated U.S. yields fell to their lowest levels in over five weeks in the aftermath of news of financial irregularities with Espirito Santo International, the largest holder of Portugal's Banco Espirito Santo.
In the futures market, the CBOT Sept 10-year T-note contract rose 13/32 to 125-12/32 to its highest in over a month on heavy volume with more than 700,000 contracts changing hands in early trading.
Wall Street stocks opened lower with the S&P 500 falling 0.6 percent. Top European share prices sank 1.4 percent.
Earlier, disappointing French inflation and factory output data compounded worries about the overall euro zone economy, spurring bets on aggressive action from the European Central Bank.
With concerns about economic weakness overseas and fighting in the Middle East, traders have brushed off more encouraging signs on the U.S. economy.
The U.S. Labor Department said on Thursday the number of Americans filing for unemployment benefits for the first time unexpectedly fell to 304,000 last week, one of the lowest weekly readings since before the 2007-2009 recession.