Can CEO Sergio Marchionne convince skeptics that Chrysler and Fiat have a solid plan in place?

These days, more and more folks talk about the “Big Two,” General Motors and Chrysler, underscoring the growing sense of skepticism about Chrysler’s long-term viability.

But that’s one of the key issues that will be addressed – though not necessarily reversed – at a meeting in Turin, Italy, on Thursday.  The man in the spotlight will be Sergio Marchionne, who serves as CEO of both Chrysler and the Italian automaker Fiat, which took control of the U.S. company after it emerged from bankruptcy, last year.

The event, at Fiat’s global headquarters, will give the Canadian-educated Marchionne a chance to lay out his 5-year plan for not only the Italian maker and its various European subsidiaries – including Alfa-Romeo, Lancia, Ferrari and Maserati – but also how the Fiat Group will fit into Chrysler’s future.

Among other things, that will mean a stepped-up presence for the U.S. maker abroad, as well as the hoped-for return of Alfa to North America, a market it abandoned two decades ago.

Specific moves will likely include the blending of the Chrysler and Lancia brands into one global brand, reports Mark Phelan, in the Detroit Free Press.  Chrysler may also be tagged to produce vehicles for Alfa, while its North American assembly plants are expected to pump out as many as 400,000 vehicles annually for the various Fiat Group brands.

Those and other steps will be critical for Chrysler if Marchionne is to achieve his admittedly aggressive plan of boosting the U.S. maker’s sales from 1.3 million to 2.8 million annually by 2013.

Considering the steady decline in Chrysler’s volume, which hasn’t been helped by recent upturns in the U.S. auto market, many observers now wonder if the company can survive, even with Fiat’s help.  Reports over the weekend even raised the prospect of having to dump one of the American maker’s remaining brands, which include Chrysler, Dodge, Jeep and the new Ram truck division.

Chrysler emerged from bankruptcy in a very different position from cross-town rival General Motors.  The federal government controls 61% of GM, though the Obama Administration has taken a largely hands-off approach to the company.  Chrysler, meanwhile, is run by Fiat, though the Italian maker only holds a 20% stake.  But Fiat’s share can rise as high as 35% if it meets several key goals, including the launch of new small cars – like the Fiat 500 – in North America, and the expansion of Chrysler’s overseas sales.

Some of those sales will come in the form of Dodge and Chrysler products marketed in Europe as Fiats or Lancias.  Meanwhile, a new product, sharing the same rear-drive platform as the Chrysler 300, will be sold here as an Alfa.  The Italian brand could also get a crossover based on the Jeep Liberty, reports Phelan.

Fiat may also use the Wednesday briefing to discuss long-rumored plans by the founding Agnelli family to spin off a separate stock on Fiat Automotive.