Exactly one year ago, squabbles over control forced Bharti Airtel and MTN to ditch their hope of forming a global telecoms group, but both emerging markets-focused companies are back on the negotiating table to thrash out a $61 billion merger.

What's changed?

MTNFor a start, both firms are now publicly talking about a detailed structure for the combined entity, something that was missing last time.

As part of an initial deal worth more than $23 billion unveiled on Monday, Bharti will pay in cash and shares for 49 percent of MTN, while MTN pays cash and stock for an effective 36 percent stake in the Indian firm. Previous merger talks collapsed when the South African firm proposed a new structure that would have seen Bharti become an MTN unit.

The past year has seen the full impact of a global recession that has spared few industries and MTN, sub-Saharan Africa's biggest mobile operator, and Bharti -- India's top mobile operator -- might be looking to combine to cope better in tough times.

Thanks to scorching growth in emerging markets, the combined entity boasts a user base of 200 million, catapulting it to the top five global industry players, while last year, the combined group would have ranked among the top ten.