Motorola has launched a legal challenge after its tender for a $6.6bn (£3.5bn) contract in India was rejected.
India is the world's fastest growing mobile market
Indian state telecom group BSNL said both Motorola and Chinese firm ZTE were disqualified on technical grounds from the bid to lay infrastructure.
The US firm said it had been in talks with BSNL but had not been given an explanation for its bid being dropped.
It is now going to Delhi High Court seeking "clarification and transparency" over the tender process.
Nokia, Siemens and Ericsson are all in the running for the contract to lay 62 million GSM lines and supply 3G equipment.
BSNL is the only firm to offer landline and mobile services across all states and territories in India.
In June, Motorola announced plans to build a $100m handset factory in the southern Indian city of Madras (Chennai).