Ex-Toyota exec to lead Fiat Auto sales.(Ruiz, Juan Jose Diaz)

TURIN, Italy - To help it rebuild market share, Fiat Auto has turned to a man who drove sales increases at Toyota, Audi and Seat.

Juan Jose Diaz Ruiz will join Fiat Auto, now a General Motors affiliate, in September as head of sales and marketing. The charismatic 56-year-old executive resigned suddenly from Toyota Motor Europe in June.

The Spaniard joined Toyota in February 1998 and pushed sales in Europe past Nissan for the first time while serving as executive vice president for sales, marketing and aftersales.

At Fiat, Diaz Ruiz will replace Carlo Sinceri, 54, who will take on other duties in the company.

Diaz Ruiz is known for his …