BERLIN—This metropolis, capital of Europe’s largest economy, is finally becoming a business hub.

In most European countries and much of the world, capital cities are also a country’s commercial nexus. But after Berlin became the capital of a reunified Germany in 1990, its orientation toward politics and lobbying resembled Washington, D.C., not the balance of business and politics found in London, Paris and Tokyo.

That is changing. Online retailer Zalando SE, digital-maps maker Here and startup-developer Rocket Internet SE have become big-name fixtures in Berlin’s new corporate landscape. Entrepreneurs and innovators increasingly are drawn to the city’s creative, open-minded ethos.

“Berlin has been experiencing fantastic development” said Christof Hellmis, vice president of strategic programs at Here, which recently was acquired by a consortium of German car companies Audi AG , BMW AG and Daimler AG . Here’s headquarters staff in Berlin has ballooned to 800 employees from a few dozen a decade ago.

New-economy companies based in Berlin rub shoulders with innovation centers of more-established tech competitors, including Microsoft Corp. , German software giant SAP SE and networking pioneer Cisco Systems Inc.

The city and its surroundings boast sizable factories of industrial companies, including German engineering group Siemens AG and British jet-engine maker Rolls-Royce PLC. Berlin is the global headquarters of railroad manufacturing for Bombardier Inc. of Canada.

The number of active, financially healthy companies in Berlin was 22% higher in July 2015 than in January 2014, according to a recent study by ratings firm Creditsafe. That rise likely outpaces the companies’ economic impact, though, because many are service businesses, such as tech startups and lobbying firms, with relatively few employees. Such firms also generally create less business for suppliers than manufacturers.

Axel Springer AG , publisher of Germany’s largest daily newspaper, Bild, and a rare company based in Berlin since before 1989, employs more than 3,000 people at its headquarters. But music-streaming business SoundCloud employs only about 200 people at its Berlin headquarters.

Still, Berlin’s expanding business community marks a return to history. Before World War II, the city was home to Siemens, Deutsche Bank and many other big companies, but the Berlin Wall and the partition of Germany ended that. West Berlin was an island inside East Germany, and its economy was heavily subsidized from the old capital, Bonn.

After reunification, unemployment in Berlin soared and local politics have tended to favor left-wing and socialist parties. The city’s reputation has been tarnished by poor management, such as a long-delayed airport project that is years behind schedule and millions of euros over budget.

One sign of Berlin’s long malaise: Rents are among the lowest of any major European capital. But rising rents indicate a growing economy, as do declining unemployment rates. Berlin’s unemployment rate was 10% in November, which is down from 19% in 2005 though far above the overall German rate of 6%. A potential upside of the unemployment rate is an available workforce, say business leaders.

Berlin’s modest cost of living and its active cultural scene are a big draw. Alexander Kudlich, a member of the executive board at Rocket Internet, said founders of many companies Rocket has helped develop “have opted for Berlin because of a high quality of life and relatively low living expenses and wages.”

But Berlin remains less international than many other major European capitals, so some foreigners struggle with language. Still, the city’s Bohemian vibe, so contrary to the stereotypical image of ultraefficient Germany, is particularly attractive to creative talent.

“Openness to everything new is something that’s very characteristic of Berlin,” said Mr. Hellmis of Here. In the city’s current evolution, he said, “it’s perhaps not the number of big industrial companies that counts but adapting to new urban lifestyles.”

In the same way that openness attracted technology innovators to the San Francisco Bay Area and Seattle years ago, it has recently attracted some to Berlin.

The city is “Germany’s Silicon Valley,” said Hans Georg Näder, chief executive of Otto Bock HealthCare GmbH, the world’s largest maker of artificial limbs by revenue. The company in 2015 opened an innovation center in Berlin and plans to relocate its headquarters there from the central German town of Duderstadt ahead of an initial public offering of stock in 2017.

Berlin’s political importance remains a major attraction for some companies, such as Bombardier, which bought a train factory near Berlin in 2001. The head office of Bombardier’s rail business has 800 employees, and about 3,000 more work at the company’s largest train factory, in the suburban town of Hennigsdorf.

“Rail-technology orders are often political decisions and public enterprises are involved,” said Bombardier spokesman Immo von Fallois. Germany’s transport minister, national railway operator Deutsche Bahn and other key players are in the capital, he said. “In Berlin, we are close to political decision makers and the transport industry.”