NEW YORK (AP) — Swiss drugmaker Roche plans to keep the chairman and chief executive of newly acquired biotech drug developer Genentech on board as chairman of the unit and named a Roche executive as its new CEO, the company said Tuesday. Arthur Levinson, Genentech's chairman and CEO, will lead the Genentech new board of directors, Roche said, and will advise Genentech's research operations. He will be nominated to join Roche's board of directors in 2010. Pascal Soriot, who now leads Roche's commercial operations, will become CEO of Genentech and lead all pharmaceutical activities in the U.S. The changes are the first look at how Basel, Switzerland-based Roche intends to integrate Genentech. Analysts have debated how heavy a hand Roche would take in management of the biotech pioneer, whose science-based corporate culture has long drawn praise. Roche completed a $48.6 billion buyout of Genentech last month and is working to combine its North American operations with Genentech. Those operations will be based at Genentech's headquarters in South San Francisco, California. Levinson and Soriot will lead the efforts to combine the companies, Roche said, with a target of finishing the integration by the end of 2009. Levinson joined Genentech as a senior scientist in 1980, has been CEO since 1995. Among other moves, the company said Genentech research executive Richard Scheller will lead an independent Genentech research center and report to Roche Group Chief Executive Severin Schwan. Several Genentech executives also will leave day-to-day responsibilities at the company behind. Among them are Genentech Chief Financial Officer David Ebersman, who will leave the company, and Susan Desmond-Hellmann, president of Genentech product development, will leave that role at midyear. Desmond-Hellmann will continue in an advisory role. The changes take effect May 1. The chairman of Roche Pharma, William Burns, will retire Jan. 1, 2010, the company said.