Peugeot's turnaround driver, Tavares, faces his biggest challenge

He's been labeled a 'restructurer-in-chief'

Former Renault star Carlos Tavares has stared down unions and slashed costs

He was credited for a turnaound at Peugeot, after it narrowly avoided bankruptcy in 2014

Now the Portuguese car fanatic and weekend racer faces his biggest challenge.

Peugeot maker PSA agreed this week to give its chief exec the go-ahead to pursue a merger with Italy's Fiat Chrysler.

Combining the two would create the fourth-largest auto maker in the world.

The two firms have outlined plans to make 3.7 billion euros of annual savings - without plant closures.

But automakers face a looming global sales slump.

Tavares himself said in September that the industry faces "ten years of chaos".

French-educated Tavares joined Renault's Japanese partner Nissan under then-CEO Carlos Ghosn.

He was tipped to be Ghosn's successor.

But Tavares grew tired of waiting and said as much in an interview.

Ghosn dismissed him, and in 2014, Tavares was hired by Peugeot to lead the turnaround.

Fiat Chrysler and PSA said on Thursday (October 31) they aimed to reach a binding deal in the coming weeks.

But analysts say the merger is unlikely to provide a quick fix to their problems in China.

They say both companies have struggled to find the right products for the world's top car market.

Scale alone may not be enough to make the group competitive in the country.

Their sales there lag behind rivals such as VW and General Motors.

Analysts say PSA does not have enough competitive SUV models or electric and plug-in hybrid vehicles.

They're also seen to lack cars packed with the hi-tech features that Chinese buyers like.