Two weeks ago, the chief executive of Nomura Holdings Inc. brought the company back into the big leagues, snapping up parts of bankrupt Lehman Brothers Holdings Inc. in Asia and Europe. Now, in his first interview with the foreign media after the deal, he says he is thinking of ways to further bolster Nomura's U.S. business, including possible acquisitions."If there is an opportunity, we want to reinforce the current operations of Nomura New York," said the 55-year-old Mr. Watanabe.

Last month, Nomura cut a deal that allowed it to gather up Lehman's people but not its debt-wracked balance sheet -- a point he demonstrated by sweeping away an imaginary pile of toxic real-estate. Now comes the hard part of locking in Lehman's top talent and swiftly melding the disparate cultures of the two companies. Rival investment banks have already hired away some high-profile Lehman employees.

Meanwhile, critics say Nomura may have a particularly challenging time in convincing Lehman bankers, who are used to a risk-taking, entrepreneurial atmosphere, to comply with Nomura's hierarchical and conservative corporate culture.

"Nomura will probably roll out the Japanese style of management," said Azuma Ohno, an analyst at Credit Suisse. "It may struggle to keep former Lehman bankers because Nomura generally pays less and its corporate culture has less of a work-life balance than foreign employees are used to."

Mr. Watanabe said the volatile financial markets have prevented petty distractions, noting that the Dow Jones Industrial Average is below 10000 for the first time since 2004."We don't have time to squabble about cultural issues, as we have something urgent to focus on," he said. Nomura expects to be over the hump of the integration process before the end of this year.

Nomura's journey back as a major player in international finance has been long and torturous. In the 1980s, Nomura became the world's largest securities house in volume, thanks in part to Japan's economic growth and a strong yen that boosted the value of its financial assets. But after Japan's stock-and-real-estate bubble burst in the early 1990s, it fell into slow decline. A scandal within Japan and heavy losses in the U.S. real-estate market in the 1990s prompted further retrenchment.

But the unfolding global financial crisis that bruised its U.S. and European rivals has presented Nomura with a rare opportunity. Nomura is feeling confident because it has kept a firm grip on market share in Japan, which is relatively sheltered from the storm. It manages about 30% of the 242 trillion yen ($2.382 trillion) that Japanese investors have in financial products.

Comparing the financial crisis to a baseball game, Mr. Watanabe, a New York Yankees fan, said he felt the game was in the ninth inning -- but was going into extra innings. There appeared to be too much pressure on the world's central banks to prop up the financial system. What was worse, the turmoil on Wall Street came at a time when there is a dangerous political vacuum developing in the U.S., he said. "I wish the U.S. election could be held quickly, even if it was tomorrow," he said.

In such an uncertain environment, the key to success requires tighter control of risk. Mr. Watanabe, who founded Nomura's risk-management team 14 years ago, said these internal policemen will be of greater importance in the post-crisis world of investment banking. Nomura is searching for a high-level chief risk officer to advise top executives, he said.

The company is also seeking less leverage -- assets that are perhaps 15 to 16 times their capital bases, instead of the 20 or 30 to 1 that some of Wall Street's firms have sported or the leverage employed for Nomura's own investments in real-estate-related securities in the U.S. That in turn means almost certainly less potential for profit and lower compensation in banking generally.

Meanwhile, Mr. Watanabe said he wanted to use the acquisition to "transform" Nomura into a more global operation. Earlier this week, the company appointed three non-Japanese senior managing directors in London. Now, former Lehman employees could potentially swell their ranks."We want Lehman staff to become part of the new Nomura," Mr. Watanabe said.