Last year, the Indian authorities relaxed their strictures on infrastructure sharing, allowing the sharing of active and passive infrastructure except spectrum. Now in more mature markets, there are moves to go even further. As growth stabilizes, governments and operators in emerging economies should start looking at this option. Two of the world’s largest cellphone operators, the Spanish company Telefónica and the British giant Vodafone, said Monday that they would share infrastructure in several European markets in an effort to cut costs and protect profit margins. The companies said in a statement that they had agreed to share networks in Britain, Germany, Ireland and Spain, and were in “detailed discussions” about doing so in the Czech Republic.