Metro Philadelphia's mix of corporate employers makes for a mellow regional economy, slow-growing but also recession-resistant.

An Inquirer survey of more than 200 major employers shows the region's biggest job engines are the hospital system affiliated with Thomas Jefferson University, and the combination of the University of Pennsylvania and its hospital network.

Other big employers include drugmakers and medical-device manufacturers such as Merck & Co. Inc., GlaxoSmithKline P.L.C. and Siemens AG; heavy manufacturers including Lockheed Martin Corp. and Sunoco Inc.; consumer-oriented media companies led by Comcast Corp. and Verizon Communications Inc.; specialized financial companies including the Vanguard Group Inc. mutual funds in Malvern and the big credit card lenders in Wilmington; and mass-market retailers, which, in this region, include national giants such as Wal-Mart Stores Inc. and home-grown companies such as hoagies-and-gasoline purveyor Wawa Inc.

Many of the region's biggest employers are in industries that tend to pay more than the national average, according to Labor Department figures. Merck, DuPont Co., Lockheed, Boeing Co., Sunoco and Exelon Corp. contribute more than their share to the region's payrolls because of the many skilled research and manufacturing positions they provide, according to industry data.

Compared with the rest of the nation, the Philadelphia area, defined for this special report as a 10-county area stretching from New Hope to New Castle, Del., and from Pottstown to Pemberton, has more than its share of jobs in higher education, and medical and health and financial services. It is underrepresented in factory, tourism and government jobs, according to Bureau of Labor Statistics data.

"Philadelphia has a broader service economy. It's world-class in health and education. That provides a very stable economy, because education and health services tend to be not nearly as cyclical as other areas," said Robert Dye, senior economist at Pennsylvania's largest bank, PNC Financial Services Group.

But Federal Reserve Bank of Philadelphia senior economic analyst Timothy Schiller worries the region relies too much on hospitals and colleges that will not, by themselves, attract more growth to the region.

"If your population is flat, the demand for medical and educational services will become flat," Schiller warns. "We need to keep evolving. We need a change in industry composition or at some point the region will stop growing, creating new problems."

Hospital boosters say the region's teaching hospitals bring in both capital and customers from beyond local boundaries. "Academic medical centers and hospitals are a key component of this thriving business sector," said Priscilla Koutsouradis, spokeswoman for the Delaware Valley Healthcare Council.

Philadelphia's major industries have their own geographies.

Drive up U.S. Route 202 through the western suburbs, and the hilly landscape of upscale tract housing and shopping centers is studded with the pill factories and research labs of the pharmaceutical industry, from AstraZeneca P.L.C. just off the I-95 exit in Fairfax, Del., up to Merck's campuses near Spring House in north-central Montgomery County.

Older suburbs closer to the city house giant military contractors like satellite- and radar-maker Lockheed Martin in Cherry Hill, Newtown and King of Prussia; Boeing's helicopter factory in Eddystone, just south of Philadelphia International Airport; and security-software-maker Unisys Corp. in Blue Bell.

The historic banks once based on Philadelphia's South Broad and Walnut Streets are gone, but a trip down the Schuylkill from Valley Forge to Boathouse Row passes some of the nation's biggest investment companies - from mutual fund leaders Vanguard Group in Malvern and SEI Investments Co. in Oaks, to highly specialized firms like Susquehanna International Group L.L.P. in Bala Cynwyd and Ira Lubert's Independence Capital Partners just west of Center City.

Northern Delaware and the Marlton-Cherry Hill corridor also are host to concentrations of financial jobs. Bank of America Corp., JPMorgan Chase & Co., Citigroup Inc., ING Groep N.V. and other banking giants moved their consumer-lending units to Wilmington in search of low bank taxes and liberal loan limits. Commerce Bancorp Inc.'s Marlton and Cherry Hill back offices are a major local employer, though the bank's planned sale to the Toronto-Dominion Bank has raised questions about its future. Commerce officials have said that it is too early to say what impact the deal might have on its employees.

PHH Corp., General Electric Co. and others also staff loan operations in the New Jersey 38 corridor.

Two of the four largest U.S. health insurers - Cigna Corp. and Aetna Healthcare - are also based in the Philadelphia area. So is Independence Blue Cross, whose planned merger with Pittsburgh's Highmark Inc. would create the No. 5 U.S. health insurer.

Most Philadelphia-area financial companies serve mass-market customers, not the high-end, boom-and-bust securities trading and investing businesses that power Wall Street and other global financial centers. With securities markets falling, "Philadelphia's in a great position not to be New York right now," said PNC economist Dye.

Center City's tallest towers house giant service companies - consumer telecom rivals Comcast and Verizon, global cafeteria manager Aramark Corp. - and the locally based law firms and consulting services that have opened branch offices across the nation and around the world as the Philadelphia banks and railroads that used to drive their business declined.

Drive down I-95 south from Center City, east on I-676 from Camden, or south on I-295 from Bellmawr, and the region's smokestack heritage survives, with DuPont's sprawling Chambers and Edgemoor works, Exelon and PSE&G power plants, Sunoco and Valero Energy Corp. oil refineries, among other chemical and industrial plants.

As head of Philadelphia-based Northern division of Wachovia Corp., the region's dominant bank, Hugh Long has taken a special role in pushing initiatives like the Chamber of Commerce of Greater Philadelphia and Select Philadelphia First that bring city and suburban companies together to promote the region as a whole.

Long said he was encouraged by the willingness of rivals such as William Mills, PNC's Philadelphia chief, and suburban business leaders such as Ernie DiAnastasis of Computer Aid Inc. in Delaware to work on joint projects with their Philadelphia counterparts. In particular, he cites the recent decision by David L. Cohen, a senior executive at Comcast and onetime chief of staff to business-friendly former Mayor (now Pennsylvania Gov.) Rendell, to serve as the chamber's next chairman.

To Long, Cohen's participation in the regional project is a powerful endorsement of regionalism by the city's biggest company.

And, Long says, Philadelphia business leaders who share a regional focus are especially hopeful about Mayor-elect Michael Nutter, who, as a city councilman representing a mix of West and Northwest Philadelphia neighborhoods, gained the respect of business leaders for articulating concern about the city's failure to contain gun violence and improve public schools.

"Nutter is a mayor we can put in front of people. The business community is just giddy over him, and he's being very well-received," Long said. "He understands it, and gets it, that if a company locates in Camden or Malvern or Wilmington, Philadelphia benefits. Some of their people will live in the city. Some of their kids will go to Philadelphia colleges. They'll watch Philadelphia sports teams. They'll be patrons at Philadelphia restaurants and cultural events."

With Philadelphia's mayor and its biggest company making overtures to their suburban counterparts and willing to share resources, Long says the area is more likely to be taken seriously in competition with Atlanta, Washington, and other East Coast markets.

"We may have been the last part of our country to start marketing itself as a region," Long said.

General Electric's local operations embody the recent shifts in the region's economy.

In the 1960s, GE's West Philadelphia factories built power-plant generators, military missile parts, and satellite components for the U.S. space program. GE and its local predecessors made radios, records and lamps.

Those factories are closed, and many of the business lines have been sold to Lockheed and other companies. GE's workforce has shrunk to 3,000, compared with 7,000 local retirees, said Ellen Mellody, spokeswoman for GE Infrastructure's Water & Process Technologies unit in Trevose.

But GE's local operations, most of which did not exist 30 years ago, now include all six of the company's major business lines - medical, industrial, infrastructure, broadcasting, and both business and consumer lending, Mellody said. GE workers fix locomotives in Philadelphia, service mortgages in Marlton, and sell environmental systems from offices in Exton.

Like the region's workforce as a whole, GE has diversified its operations, focusing more on profitable services and manufacturing for growth fields such as medical equipment.

"We're very engaged in this community," Mellody said.