Population growth in the Dallas-Fort Worth region has slowed, but the area still added more people in 2006-07 than any other metropolitan area in the country, according to new U.S. Census Bureau statistics.

The figures, to be released today, show that the Dallas-Fort Worth metro area – the nation's fourth-largest – increased by an estimated 162,250 in population to top 6.1 million residents. That placed it ahead of sprawling metropolises Atlanta and Phoenix in sheer numerical gain.

The metropolitan-level estimates come a week after census officials released data showing that several North Texas counties had grown at a slower pace in 2006-07 than the previous year. Overall, the D-FW area grew at a rate of 2.7 percent.

But other hot growth areas from years past added fewer people than Dallas-Fort Worth. And Houston, last year's largest numerical gainer, didn't see an influx of hurricane evacuees in 2006-07, as it did the year before.

The D-FW region was one of four metro areas in Texas that ranked among the nation's top 10 population gainers in 2006-07, including Houston, Austin and San Antonio. Experts credit that to the state's relative economic strength and the delayed effects of a housing slump that have yet to take shape in the census data.

"The past couple of years in Texas have been similar to the energy boom in the late '70s and early '80s because of our economic strength relative to the rest of the country," said Fiona Sigalla, an economist at the Dallas Federal Reserve.

The data showed that the New Orleans area added nearly 40,000 people last year, a huge swing from the 290,000 it lost the year before after Hurricane Katrina.

Meanwhile, Detroit declined by more than 27,300 to fall out of the top 10 largest metropolitan areas and was passed by Atlanta at No. 9.

The estimates run from July 2006 to July 2007, so they reveal little of the housing crisis and credit crunch that has gripped the U.S. since then.

One sign may appear in Dallas-Fort Worth's international immigration figures. The area experienced a drop of roughly 10 percent to 39,000 new immigrants, down from about 43,000 the year before.

Pia Orrenius, another economist at the Dallas Fed, said several factors could be in play, including a slowing construction industry.

"The busted housing market has been worse here than in the rest of Texas," she said. "We in North Texas tend to reflect the national economy more than the rest of Texas."

Roughly a fifth of foreign-born Latinos in Texas work in construction, compared with 15 percent nationwide, Ms. Orrenius said. Nationally, single-family housing starts began slowing two years ago this month, so it was only a matter of time before the effects were felt here.

Further, Ms. Orrenius said, greater immigration enforcement in the past year has meant that it is likely that fewer immigrants are crossing into the U.S.

"We've had a big drop-off in border apprehensions since a year ago," she said.

The overall population is estimated by combining natural growth – births minus deaths – with population increases by international immigrants and residents from other areas of the U.S.

In 2006-07, births rose by 4,200 compared with the year before, effectively offsetting the decrease in international immigrants.

Today, a third set of local population estimates will be released, this time by the North Central Texas Council of Governments. Because they cover up to Jan. 1, and because they are based more on housing statistics, they could reflect more recent economic trends than the census figures.

Overall, a gradual population slowdown has been evident in the two weeks of census data. For instance, Collin County is still growing, but it recently lost its spot as the fastest-growing county in the U.S. of more than a half-million people. Fort Bend County, near Houston, took its spot.

In recent years, the Dallas-Fort Worth area has pushed past Philadelphia to become the nation's fourth-largest metropolitan area. Promoting that idea is critical, said Lyssa Jenkens, chief economist of the Greater Dallas Chamber.

"It is amazing what people ask about Dallas-Fort Worth," Ms. Jenkens said. "We get questions like, 'We want to move our company, but does Dallas have 50 engineers?' We have grown so fast ... you can't blame people for being surprised."

Katrina evacuees notwithstanding, the number of people who moved to this region from elsewhere in the U.S. was about the same in 2006-07 as the year before. Those were also the first two years since 2000 in which internal migration was greater than international migration.

To Ms. Jenkens and Ms. Sigalla, that means the Texas economy remains stronger than other parts of the country and therefore continues to attract workers. Ms. Jenkens said continued growth will present challenges.

At the beginning of what she calls the "modern era" in the mid-1970s – when Dallas/Fort Worth International Airport become operational and united two local economies – the region had excess capacity to handle growth, she said.

"Now we're at the limits; we're using everything we have," Ms. Jenkens said. "We're going to have to be a lot smarter than we have."

Ms. Jenkens said the Dallas chamber is looking to other metro areas that have met similar challenges, such as Chicago, Boston and Seattle. But some of the answers are not yet apparent for Dallas-Fort Worth.

"I think part of it is being willing to take the long-term look," she said. "And the business community will be our innovators."