By Mathieu Rosemain

PARIS (Reuters) -Societe Generale's shares soared on Thursday after CEO Slawomir Krupa shook up his management team and the French bank beat profit forecasts, while rival BNP Paribas' stock slid following mixed quarterly results.

The banks both reported better than expected investment banking sales, but differing performances in their retail businesses and on other key metrics led investors to react in opposite directions.

SocGen shares had jumped more than 11% by 1415 GMT, propelling them into positive territory for the year. BNP by contrast fell 5%, putting it on course for its biggest daily loss since May and leaving the shares down year-to-date.

For SocGen, which had struggled to convince investors of its turnaround plan since Krupa took the reins last year, the third-quarter beat was driven by a rebound in its French retail business, prompting several analysts to say the division had reached a long-awaited turning point.

That is seen as key to boosting investors' confidence as the division accounts for close to a quarter of SocGen's pre-provision profits, according to UBS.

Krupa also replaced his finance chief Claire Dumas with Leopoldo Alvear, chief financial officer at Spanish bank Sabadell, and took direct supervision of French retail activities, seeking to draw a line under past setbacks in that business.

"I'm not trying to prove anything to anyone," he told reporters in a call, when asked about the management reshuffle.

"In retail banking, things are in the process of turning around, but it was necessary to change the team," he added.

Citi analysts said Krupa appeared more upbeat on the earnings call than previously about delivery, with the "old-drags" such as French retail mostly behind it.

"While it is a strong reaction (in the shares), this can be justified", the analysts said, pointing to the bank's low valuation as well as Krupa's efforts.

The bank's share price has risen nearly 11% since Krupa took over in late May 2023, versus a 37% rise in European banks as a whole.

SocGen said Philippe Aymerich was stepping down as deputy CEO and relinquishing responsibility for French retail operations, with two new co-heads appointed to manage the French retail network.

Alvear will start from Jan. 7. He held the same role at Sabadell, currently the subject of a hostile takeover bid.

EXPECTING MORE

SocGen's third-quarter net income more than quadrupled from a year earlier to 1.37 billion euros ($1.5 billion), beating the 1.22 billion euro median forecast of 16 analysts compiled by the company.