NEW YORK -- Encouraging economic reports pushed stocks higher Thursday, driving the Dow Jones industrial to its third gain in a row.

The number of people applying for unemployment benefits dropped last week to the lowest level since April 2008, the latest sign that the job market is healing. It was the third week in a row that applications fell. The Conference Board also reported that its measure of future economic activity had a big increase last month. It was the second straight gain.

The government lowered its estimate of U.S. economic growth in the July-September quarter to an annual rate of 1.8 percent from 2 percent. That was still the fastest growth this year, up from 1.3 percent in the April-June quarter.

Nuke reactor to be used in S.C. approved by feds

WASHINGTON -- Federal regulators have approved a nuclear reactor designed by Westinghouse that could power the first nuclear plants built from scratch in this country in more than three decades.

The Nuclear Regulatory Commission on Thursday unanimously approved the AP1000 reactor, which will be used to expand the V.C. Summer station north of Columbia. The certification, effective immediately, is valid for 15 years.

NRC Chairman Gregory Jaczko said the plants using the design could withstand damage from an airplane crash without significant release of radioactive materials.

Approval of the design is a major step forward for utilities in Georgia, Florida and the Carolinas that have billions of dollars riding on plans to build AP1000 reactors in the Southeast. Without approval, the companies could not have gotten a license to build.

American Air is cleared to proceed with Boeing

NEW YORK -- A bankruptcy judge ruled Thursday that the parent of American Airlines can go ahead with its previously scheduled deliveries of 32 Boeing aircraft next year. The decision allows AMR Corp. to continue renewing its fleet even though it filed for bankruptcy protection on Nov. 29.

An attorney for AMR also told the judge that there has been no noticeable decline in passengers since the filing.

Mortgages fall to record low for home borrowers

WASHINGTON -- The average rate on the 30-year fixed mortgage fell to a record 3.91 percent this week, the third time this year that rates have hit new lows.

Freddie Mac said Thursday that the average on the 30-year home loan fell from 3.94 percent the previous week. The average on the 15-year fixed mortgage was unchanged at 3.21 percent, also a record.

Low rates offer a historic opportunity for those who can afford to buy a home or refinance. But many either can't take advantage of the rates or have already done so.

Rates could fall further still. Many experts think the yield on the 10-year Treasury note could creep lower. Long-term mortgage rates tend to track that indicator.

Vulcan Materials sues suitor over hostile offer

INDIANAPOLIS -- Vulcan Materials has filed a lawsuit against Martin Marietta, accusing the smaller gravel and stone supplier of launching an illegal takeover bid using confidential information.

Vulcan strongly recommended to its shareholders Thursday that they not tender their stock to Martin Marietta, which announced a hostile bid earlier this month.