FRANKFURT (AFP)--Italian auto maker Fiat SpA (F.MI) has raised its offer for troubled German rival Adam Opel AG to EUR1 billion, a labor leader told AFP Monday.

"Fiat has raised its offer a little to EUR1 billion," Rainer Einenkel, head of the Opel works committee at Opel's factory in Bochum in west Germany, said.

Another German union leader, Armin Schild, had said previously that the offer was worth less than EUR750 million.

But Einenkel, who works at the Opel plant in western Bochum, said one billion wasn't enough, noting that Opel needed EUR3.3 billion to keep running and develop further.

Fiat has not yet unveiled a true "financial plan and production plan," he added.

Several meetings were scheduled Monday between Fiat boss Sergio Marchionne and German leaders, including Economy Minister Karl-Theodor zu Guttenberg and Vice Chancellor and Foreign Minister Frank-Walter Steinmeier.

Steinmeier said during a visit to another Opel plant in eastern Eisenach that Fiat was only one of several interested parties and that was "not decision time yet."

"Interested parties first have to fine tune their plans and then hopefully we will come to decisions in the coming weeks," Steinmeier told a news conference.