TURIN, ITALY -- Fiat SpA plugged a power vacuum in its upper ranks yesterday when it named Italian-Canadian turnaround expert Sergio Marchionne to be its fifth chief executive officer in two years, pushing its shares to their highest level in a month.

Mr. Marchionne, who was the investor-friendly CEO of Swiss testing services firm Société Générale de Surveillance and a Fiat director, immediately pledged to stick to the turnaround plan drawn up by his predecessor, Giuseppe Morchio, who quit unexpectedly on Sunday.

"The plan was approved by the board. We have every intention of completing it," he told reporters, easing fears about another course change for the money-losing giant.

Mr. Marchionne was part of the board that passed the plan.

However, he hinted that there might be more changes ahead as he evaluates the managers Mr. Morchio brought in to breathe new life into Italy's biggest industrial group.

"I don't know them well enough. We need to start working and see what happens," Mr. Marchionne said. "I know the team we have has good potential, we just need to tap it. I've done this before."

Mr. Marchionne is a hard taskmaster who sets tough targets and expects people to meet them.

At SGS, he stripped down management to save cash. As chairman of the Swiss chemical firm Lonza Ltd., he was instrumental in the resignation of a CEO after bad results.

Mr. Marchionne, 51, arrives two days after Fiat's controlling Agnelli family named Ferrari chief Luca di Montezemolo as chairman to replace Umberto Agnelli, who died last week. Mr. Morchio, who wanted the top job, quit as a result.

Fiat stock closed up 4.6 per cent at an even 6 euros while the DJ Stoxx European index of auto stocks fell 1 per cent. SGS closed more than 8 per cent lower.

The new appointments were hailed as a sign that the Agnelli family did not plan to loosen its ties to the auto maker an ancestor founded 105 years ago. Instead, they named the most prominent member of the younger generation, John Elkann, as vice-chairman.

Mr. Montezemolo said Mr. Elkann, 28, would have an operative role at Fiat, not just sit on its board and strategy committees.

Mr. Elkann said the new team would speed up Fiat's recovery plan, which hopes to drag the tractor-to-parts group back to full profitability in 2006.

To do that, analysts said Fiat needs to boost its top line as fast as possible or sell assets. Last year, revenue fell 7 per cent and car sales dropped 10 per cent.

A slump in car sales -- 42 per cent of group revenues -- was one of the main reasons Fiat tumbled to a record loss in 2002. It plans to launch several new or remodelled cars by the end of 2006.

One analyst described Mr. Montezemolo and Mr. Marchionne as a "good cop, bad cop" team, with Mr. Marchionne driving employees for "hard work and commitment."