* 43-year old son of largest single Tata shareholder
* Brother-in-law of Ratan Tata's half-brother
* Boardmember of Tata Sons since 2006
By Henry Foy
MUMBAI, Nov 23 (Reuters) - His surname may not be Tata, but Cyrus Mistry is as close as an outsider could come.
Announced on Wednesday as the heir apparent to Ratan Tata, the group's long-standing chairman, Mistry will become head of one of India's most storied business groups.
A five-man selection team - which included the 43-year-old Mistry himself - spent 15 months searching for a successor to 73-year-old Tata, in a closely guarded process that had India Inc guessing.
In the end, the panel didn't have to look far.
Mistry's grandfather first bought shares in Tata Sons in the 1930s, a stake that currently stands at 18.5 percent in the hands of Mistry's father, Pallonji Mistry, the largest single shareholder in a firm mostly controlled by trusts.
The chairman-in-waiting, who will head a group with revenues in excess of $83 billion, is brother-in-law to Noel Tata, Ratan Tata's half-brother. Noel Tata was considered by many observers to have been the front-runner in the race for the chairmanship.
Mistry's father, a reclusive billionaire with an estimated wealth of $7.6 billion according to Forbes, paved the way for his younger son's ascendancy to the top of a group founded by Ratan Tata's great-grandfather.
In Tata circles, Pallonji is dubbed the "Phantom of Bombay House" for the quiet but assured way he commands power around the south Mumbai headquarters of the Tata empire.
When Pallonji retired from the board of Tata Sons in 2006, having been granted a year's extension past the 75-year age cap, his then 38-year-old son stepped into his shoes.
According to Ratan Tata, he didn't let the family name down.
"I have been impressed with the quality and calibre of his participation, his astute observations and his humility," Tata was quoted as saying in a statement on Wednesday.
"He is intelligent and qualified to take on the responsibility being offered."
Mistry will be the sixth chairman of the group and the second not named Tata.
Two fund managers with holdings in Tata Group companies who wished not to be identified told Reuters that Mistry is relatively unknown in Indian business circles.
"I'm surprised, yes, but at the end of the day he is not controversial, given his position as the largest shareholder," A.M. Naik, chairman of engineering conglomerate Larsen & Toubro told Bloomberg UTV news channel.
The youngest of Pallonji's two sons, Mistry has two sisters and is married to Rohika Chagla, daughter of a prominent lawyer. Known for sharing his family's love of horses, Mistry describes himself as a voracious reader of business books and a golfer.
A civil engineering graduate of Imperial College, London, the bespectacled Mistry has a Master's of Science in Management from the London Business School, and was until Wednesday the managing director of the Shapoorji Pallonji Group.
He resigned from that post after his nomination was announced in order to avoid possible conflicts of interest.
"I feel deeply honoured by this appointment. I am aware that an enormous responsibility, with a great legacy, has been entrusted to me," Mistry said in a statement on Wednesday.
"I look forward to Mr Tata's guidance in the year ahead in meeting the expectations of the Group."
Mistry, who received unanimous backing from the selection committee, becomes Tata's deputy chairman immediately and will work alongside Ratan Tata for the next 12 months before taking the reins of the Group in December 2012.
He is no stranger to the stresses and strains of life at the top of a vast business empire, having headed his family's Shapoorji Pallonji Group since 2003, where he oversaw revenues in excess of $2 billion.
A 147-year-old firm, Shapoorji boasts the tallest residential building in India and the largest cement clinker plant in Asia.
"I thought him to be a very sharp and astute business person," Ajay Piramal, chairman of India's diversified Piramal Group, told the NDTV Profit news channel.