* Traders anticipate hawkish Yellen stance Tuesday
* Concerns ease over Portugal's top bank
By Sam Forgione
NEW YORK, July 14 (Reuters) - U.S. Treasuries prices slipped slightly on Monday on expectations that Federal Reserve Chair Janet Yellen could take a less accommodative stance on interest rates in a congressional testimony on Tuesday.
Yellen, who will go before the Senate Banking Committee early Tuesday to deliver the latest report to Congress on monetary policy, could take a hawkish stance on raising interest rates in response to strong June jobs data, analysts said.
"Given some of the strong data that we've had recently since her last speech, there's at least some expectations of her acknowledging that," said David Thielke, interest rate strategist at Nomura Securities in New York. "If anything, the risks are skewed to the hawkish side."
Yellen is also set to speak before a House committee on Wednesday. The Fed chief delivers testimony on monetary policy twice a year to Senate and House committees.
Private-sector jobs and nonfarm payrolls growth in June beat expectations, while the unemployment rate fell to a near six-year low of 6.1 percent. Traders are watching the Fed closely for signs of when the central bank will raise rates, which will hurt bond prices.
Analysts also said the installment of a new chief executive at Portugal's top bank, Banco Espirito Santo, and a statement that the bank's main shareholder had sold a 4.99 percent stake eased concerns of potentially destabilizing losses at the bank.
Benchmark 10-year U.S. Treasury notes were last down 5/32 in price to yield 2.54 percent, from a yield of 2.52 percent late Friday. U.S. 30-year Treasury bonds were last down 4/32 to yield 3.35 percent, from a yield of 3.34 percent late Friday.
Analysts said upcoming remarks from European Central Bank President Mario Draghi would likely have little effect on Treasuries prices. Draghi will address a European Parliament committee in Strasbourg later on Monday.
"There is a lack of fresh news for him to dwell upon," said David Keeble, global head of fixed income strategy at Credit Agricole in New York.
On Wall Street, U.S. stocks opened higher, boosted by the latest flurry of merger activity as well as strong earnings from Citigroup Inc. The benchmark S&P 500 stock index was last up 0.54 percent.
(Reporting by Sam Forgione; Editing by Meredith Mazzilli)