For Read it's a "step-up" role, after a good track record at Vodafone, said James Ratzer, a telecom analyst at New Street Research in London.
Colao was appointed chief executive in July 2008 and in his 10-year tenure has seen Vodafone transformed from a consumer-focused 2G/3G mobile operator into one of the world's leading converged communications companies. The merger announced previous year of Vodafone's unit in India with Idea, created to let the two combat a raging price war in the world's second-largest mobile-phone market, is also awaiting final approvals.
In 2012, the Supreme Court of India ruled in favour of Vodafone but government made amendment in tax regime same year and served notice to the British firm again. She was previously Group Chief Financial Controller, Chief Financial Officer for the Europe region, and Chief Financial Officer for Vodafone Italy.
"After 10 years of stability under Colao, Vodafone is potentially setting sail into uncharted waters under the guidance of an executive that has been with the company only 4 years and has less top level experience than the markets would have been fully comfortable with", said Artjom Hatsaturjants, research analyst at Accendo Markets.
Vodafone Group chairman Gerard Kleisterlee said: "On behalf of the board, I would like to express our gratitude to Vittorio for an outstanding tenure".
Having finally sealed what looks like a significant and strategically beneficial European cable network deal with Liberty Global, Vodafone now looks to be in a far stronger position in a converged digital communications future.
"Our sustained investment in network quality supported robust commercial momentum", he added.
Excluding the negative impact of net roaming declines in Europe, the benefits of settlements in the United Kingdom and Germany and the introduction of handset financing in the United Kingdom, organic adjusted EBITDA grew by 7.9%. "It is the right time ... to start with a new dedicated management team".
News of Colao's departure comes after the group recently announced a €18.4-billion deal to buy Liberty Global's operations in Germany, the Czech Republic, Hungary and Romania.