Tellabs has named former Alcatel executive Krish Prabhu as its new president and CEO.Prabhu, formerly the CEO of Alcatel's U.S. operations, had been a venture capitalist with Morganthaler Ventures until his appointment by Tellabs this week.Tellabs built its business on becoming the leading supplier of digital cross-connects to carriers. But over the past three years, the company has made acquisitions - notably IP\/MPLS service-switch vendor Vivace and next-generation multiplexer vendor Ocular - to broaden its product lines and maintain its customers.The company went through several rounds of layoffs two years ago as telecom spending fell but has remained profitable. Its sales have declined steadily since 2001 from $2.2 billion to $981 million last year.The CEO spot opened up because Michael Birck, the company's chairman and now former CEO, plans to retire in April. He announced his plans last fall.Birck took over after Tellab's former North American CEO -- and Ocular founder -- Edward Kennedy withdrew his name from consideration for the top spot last month after then-CEO Richard Notebaert left to take up the reins at Qwest. Kennedy has since resigned, citing personal reasons.