Cisco Systems Inc. Thursday announced the appointment of Charles Giancarlo to be chief development officer, replacing the retiring Mario Mazzola. The move is effective July 31.

Mazzola has served 12 years in a number of engineering leadership roles at the networking company, and Cisco CEO John Chambers credited him with developing a world-class engineering group and ?solidifying our reputation for innovation and risk-taking.?

Giancarlo will report to Chambers and oversee a 14,000-member engineering group. Giancarlo will also continue in his current role as president of Cisco-Linksys LLC, an independent division that makes Wi-Fi routers and related products for the consumer and small business markets.

Zeus Kerravala, an analyst at Yankee Group Inc. in Boston who closely covers Cisco, said Mazzola was a strong leader and called Giancarlo ?a very strong replacement.? The move means Cisco, which dominates global sales of routers and switches, ?will keep on ticking,? he said.

Giancarlo has been at Cisco since December 1994.

Cisco also announced expanded roles and promotions affecting several other top executives.