Rate jitters could hit stocks again

NEW YORK (CNNMoney.com) -- U.S. stocks could have trouble again Tuesday as investors worry about the state of the economy and interest rates.

Stock futures were down in early trading, pointing to a lower open, after major indexes all pulled back Monday following comments from Fed Chairman Ben Bernanke that stirred concerns that the Fed might be leaning more towards a rate hike rather than a rate cut as its next move.

Treasury prices were little changed, leaving the yield on the closely watched 10-year note near the 4.99 percent level reached late Tuesday. The rate rising above the 5 percent psychological threshold for the first time since August could itself weigh on stocks.

In another concern for interest rates, the Labor Department revised its reading on worker productivity down to a 1.0 percent gain in the first quarter from its original estimate of a 1.7 percent rise. That met the estimate of economists surveyed by Briefing.com, but it's a concern because it raised the increase in unit labor costs to 1.8 percent from a modest 0.6 percent rise in the original estimate. Lower productivity increases inflationary pressures that go with economic growth, so the lower productivity reading could still raise rate concerns further.

In corporate news, online brokerage TD Ameritrade Holding (Charts) announced late Tuesday that hedge funds JANA Partners and S.A.C. Capital Advisors have revealed that they have an aggregate "economic interest" in about 8.4 percent of its shares and that they want the company to pursue a merger. They were suggesting a combination with either Charles Schwab (Charts, Fortune 500) or E*Trade Financial (Charts). But a spokesman for Schwab said Tuesday that, "We don't see any significant strategic advantage that such an acquisition would provide." Shares of TD Ameritrade shot up 9.3 percent in after-hours trading.

Online auctioneer eBay (Charts, Fortune 500) said Tuesday it is set to begin auctioning advertising airtime on 2,300 participating U.S. radio stations, expanding on an existing plan to sell cable television ads. All major radio operators have joined the radio ad auction market, including No. 1 radio broadcaster Clear Channel Communications (Charts, Fortune 500), eBay said. The move puts eBay into competition with Web search leader Google's (Charts, Fortune 500) recent move into the field. Shares of eBay gained 0.4 percent in after-hours trading.

Oil prices were lower ahead of the 10:30 a.m. ET report on U.S. fuel inventories. U.S. light crude lost 7 cents $65.54 a barrel in electronic trading.

The dollar was lower against the yen but slightly higher against the euro following a rate hike from the European Central Bank, coupled with strong a strong warning in its statement on inflation risks that raised expectations of at least one more rate increase ahead.

Stocks in Asia closed mixed, while major markets in Europe were mostly higher in early trading.