Mergers and acquisitions are not new to Indian telecom industry but once again it is in news as country's second and third telecommunication service provider Vodafone and Idea has recently announced their merger plans.

Meanwhile GizBot takes a look at the major deals that have happened over a period of time.

Here are the M & A in India

Vodafone – Hutchison Essar Merger in 2007 This is one of the largest deals that happened in telecom industry on February 11, 2007. The company said that it would buy the stake of 67 per cent in Hutchison Telecommunications International, a unit of Li Ka-shing's Hutchison for $11.1 billion and the company become India's No. 2 telco by subscribers.

The company is now called Vodafone India after Vodafone Group Plc. raised its stake to a 100 per cent in the entity.

Idea buys 80% in Spice telecom

Aditya Birla group's Idea Cellular bought BK Modi's Spice Communications for over Rs 2,700 crore and now the former owns more than 80 per cent equity in the latter which is now a subsidiary of the Mumbai-based telecom operator. Idea Cellular acquired the company from Modi Wellvest and Telekom Malaysia (TMI, now Axiata) in July 2008.

Telenor buys Unitech Wireless

Telenor, a Norway-based international telecommunication service provider bought 49 per cent stake in Unitech Wireless the telecom arm of the realty firm, Unitech, in two tranches for Rs 2,380 crore. However the company had raised its stake to over 60 per cent, but like Etisalat, saw its joint venture's licenses cancelled by the Supreme Court in 2012.

It has however stayed put in the Indian market, bought back licenses in some circles, took control of the joint venture after Unitech exited it. Telenor now owns 100 per cent of its Indian unit. The company had rebranded itself to Telenor India from Uninor.

Reliance Industries – Infotel merger

Mukesh Ambani owned Reliance Industries bought 95 per cent stake in Infotel Broadband for Rs. 4,800 crore in June 2010. The company has already shaken the market by announcing its 4G plan. It is also offering cost-free unlimited voice call, and data offer to its users. The offer will end on 31st March and after that Jio will charge for data and voice calls.

It has already introduced its entry-level Rs 149 plan for free data and voice calls which will come into power from 1st April 2017.

Reliance Communications – Aircel merger

In the biggest consolidation deal in the telecom sector, Reliance Communications Ltd led by Anil Dhirubhai Ambani has announced its plan to merge with Aircel. If the merger comes through then the new entity will create a telecom operator ranked fourth by customer base and revenues and number three operator by revenues in 12 important circles.

RCom and Maxis Communications Berhad (MCB) of Malaysia, which owns Aircel, will hold 50 per cent each in. The merged company will be one of India's largest private sector companies, with an asset base of over Rs 65,000 crore and net worth of Rs 35,000 crore ($5.2 billion).

Vodafone – Idea merger

This news comes as surprise for the Indian telecom sector. The proposed merger between both the entities will create with a subscriber base of more than 400 million to emerge as the largest player in India and will displace Bharti Airtel, which currently has over 260 million users on its network.

Vodafone also confirmed the news and says, "Vodafone confirms that it is in discussions with the Aditya Birla Group about an all share merger of Vodafone India - excluding Vodafone's 42 per cent stake in Indus Towers - and Idea.

"Any merger would be effected through the issue of new shares in Idea to Vodafone and would result in Vodafone deconsolidating Vodafone India," it said.

Country' s three leading mobile operators, Bharti Airtel, Vodafone and Idea, are under pressure due to the arrival of Mukesh Ambani led Reliance Jio, which has shaken up the market by offering free voice and data to customers.