* Buys Essar tower unit for enterprise value of $432 mln
* Essar tower unit has 4,450 mobile towers
* Third Indian acquisition for American Tower in about a yr (Adds confirmation from companies, writes through)
NEW DELHI, Feb 24 (Reuters) - Telecoms tower firm American Tower Corp (AMT.N) will buy India's Essar Group's tower unit for 20 billion rupees ($432 million) in equity and assumed debt, to expand in the world's fastest-growing mobile market.
American Tower has agreed to buy the share capital of Essar Telecom Infrastructure in an all-cash deal, the companies said.
This would be the third acquisition in India in about a year for U.S.-based American Tower, which is expanding in the country and has bought local tower firms Xcel Telecom and Transcend.
India's telecom tower industry is going through a consolidation phase as smaller firms are opting for mergers or alliances in an effort to be more cost effective and take on larger rivals.
Last month, Essar's competitor GTL Infrastructure (GTLI.BO) agreed to buy mobile firm Aircel's telecom towers for $1.8 billion, adding 17,500 towers to its existing 14,500.
Essar Telecom Infrastructure has about 4,450 wireless communications tower sites, including some under construction, the companies said in a joint statement on Wednesday.
American Tower owns about 2,000 tower sites in India, and more than 26,000 globally, according to its website.
The Economic Times reported the deal earlier on Wednesday and cited a total $450 million valuation, that included $300 million in equity and assumption of $150 million of debt held by Essar's tower unit.
A source had also told Reuters the deal was being valued at $450 million, including some debt, but the companies did not disclose the debt being factored into the enterprise valuation.
Barclays Capital (BARC.L) acted as financial adviser to Essar for the deal, the statement said, adding the companies expect to close the deal in about three months time. ($1=46.3 rupees) (Editing by Surojit Gupta and Sharon Lindores)