“New York’s ability to compete with London, which has much more open immigration, or with the emerging financial capitals in Asia and the Middle East, depends on mobility of talent, both in terms of new and current employees,” said Kathryn S. Wylde, president of the partnership. “What people miss is, New York’s standing as an international capital of business and finance depends on the professionals within these companies being able to come to New York to be trained and groomed for leadership positions around the world.”

Indeed, companies are capitalizing on more open visa policies elsewhere to recruit some of the leaders educated and trained in New York. Gaurav Gaur, for example, an Indian who earned his M.B.A. from Cornell in 2004, said he seized the chance to leave New York last year for London to work for Barclays, though it meant turning his back on opportunities at Bloomberg L.P. and other American companies.

“The whole visa situation was one of the biggest reasons that I took the job,” Mr. Gaur said in a telephone interview from London, where he is a senior project manager for the British bank. “I didn’t want to keep going through this uncertainty  it’s just a nightmare.”

In New York, Mr. Gaur, 33, had managed to secure one of the three-year visas for professionals known as H-1B visas, and he probably could have renewed it for another three years, he said. But after that he knew he would be faced with the prospect of year-to-year renewals while he waited in a long and unpredictable line for permanent residency  and remained tethered to whatever company was sponsoring him for a green card.

Moreover, he said, his wife, Bhavna, who has a master’s degree in social work from Washington University in St. Louis, had work visa woes of her own in a field where few employers were familiar with the H-1B program.

In Britain, he said, “it’s drastically different.” There is no cap on work visas, and since he had a work permit, his wife was automatically allowed to work; she quickly found a good social work job.

“If I stay here for five years,” he added, “I automatically become eligible for a green card, for permanent residency.”