U.S. stocks slipped on Wednesday after Portugal's credit rating was cut on deficit concerns, prompting a sell-off after the recent rally.

The three major U.S. stock indexes slightly added to the session's losses after a weak auction of five-year U.S. Treasury notes.

The Portugal credit rating downgrade added to worries about overseas debt, with Greece's debt problems dominating the spotlight since early January.

Chevron Corp helped pull the Dow lower, falling 1.2 percent to $73.88 after the price of oil fell 1.6 percent to $80.53 a barrel. Concerns about Portugal's credit downgrade pushed the dollar up against the euro, hurting the prices of dollar-denominated commodities like oil. An increase in U.S. crude stockpiles in the latest week also hit oil prices.

I think people are looking for a reason to take some profits, given the overbought nature, and the much stronger dollar over the Greece concerns and Portugal's debt being downgraded is providing that reason today, said Michael James, senior trader at regional investment bank Wedbush Morgan in Los Angeles.

The Dow Jones industrial average <.DJI> was down 44.74

points, or 0.41 percent, at 10,844.16. The Standard & Poor's 500 Index <.SPX> was down 5.65 points, or 0.48 percent, at 1,168.52. The Nasdaq Composite Index <.IXIC> was down 13.90 points, or 0.58 percent, at 2,401.34.

Before the weak Treasury note auction, the Dow and the S&P 500 were each down about 0.2 percent, while the Nasdaq was down about 0.4 percent.

The session's declines follow the market's push to 18-month highs on Tuesday, with the Dow racking up a 10th day of gains out of the past 11 sessions.

For the month so far, the S&P 500 is up 6 percent.

Helping to limit the Dow's losses, though, Boeing Co rose 0.7 percent to $72.65 after a brokerage raised its rating on the stock to outperform from neutral on prospects for improved revenue.

One of the biggest drags on the Nasdaq was Genzyme Corp , down 6.4 percent at $55.33, after the company said the U.S. Food and Drug Administration will take enforcement action at one of its plants. Genzyme makes drugs to treat rare and chronic diseases.

Google also weighed on Nasdaq, falling 0.4 percent to $547.00, two days after shutting its Chinese portal over censorship.

The session's data sent mixed signals about the economy, with new home sales unexpectedly falling to a record low in February. In contrast, new orders for durable goods, which include long-lasting manufactured products such as washing machines, rose for the third straight month in February. Inventories of durable goods posted their biggest gain since December 2008.

Bank of America Corp ranked among the Dow's major advancers, rising 2.5 percent to $17.55 after it said it plans to offer about $3 billion in loan forgiveness to about 45,000 troubled homeowners. The move is an effort to prevent foreclosures when home values drop sharply below the amount owed.

(Reporting by Caroline Valetkevitch; Additional reporting by Leah Schnurr; Editing by Jan Paschal)