"A lot hangs in balance" for several new heads of prominent global companies next year, according to the Wall Street Journal, which said that the corporate world will be watching these leaders.

At stake is "reputations, money and survival", said WSJ of the 12 prominent heads of global companies.

Mistry has a year to learn the ropes of how to run one of the most successful and respected business empires in India, while he does his apprenticeship with outgoing chairman Tata, who retires in December 2012, it said.

"Does he have the business chops or is he just there because of his father? That's the question hanging over Cyrus Mistry, the 43-year-old heir apparent at India's flagship conglomerate, Tata Group," WSJ said, adding that Mistry will have time to learn on the job "before the answer becomes clear".

Mistry's curriculum vitae touts his achievements as Managing Director of his family's construction firm, Shapoorji Pallonji & Co. However, his father, reclusive billionaire Pallonji Mistry is the biggest shareholder in Tata Sons, Tata group's holding company, with a stake of about 18 per cent, WSJ said.

The other top executive to "watch in 2012" is Cook, who took over the reins of the technology giant Apple in August, just two months before the company's iconic co-founder Steve Jobs passed away.

"In his 10-plus years with Apple Inc, Cook has proved he's a whiz at running the technology giant's operations. In 2012, the world will learn how comfortable he is being the frontman too," WSJ said.

So far, Cook has received high marks from employees and investors who find him "affable but demanding" and who feel he has dug into Apple's operations and products with a similar attention to detail as did Jobs.

"Next year will bring another set of tests: Cook will likely take the stage as Apple trots out new versions of old devices, like the iPhone and iPad, and possibly some brand-new products, like a much-anticipated Apple television," the paper

said.