Both the football club and the carmaker are controlled by the Agnelli family through their holding company.
The USB union believes the decision is causing Fiat to miss out on investment, which the transfer money could have been used for.
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He said the players were " absolutely gutted " but the fans' reaction in the stadium after the game showed what they had achieved. Paul Merson gives his prediction and picks his key player.
Juventus' supporters show Cristiano Ronaldo's official Juventus jerseys.
The union urged Fiat owners to invest in its workforce to bolster the finances of "thousands of people instead of only one".
"It's unacceptable that, while FCA and CNHI workers continue to make huge economic sacrifices, the company spends hundreds of millions of euros on the purchase of a player", Lavoro Privato, a spokesperson for the Union of Base Workers Syndicate, said in a statement. "I wish him all the best except when he is playing against Madrid". The factory is just one of seven Fiat Chrysler plants in Italy and the USB does not represent many workers there.
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And Abramovich is said to be ready to sell Hazard as he is considering selling the club, although he has not yet received an offer.
Workers at a Fiat Chrysler plant in Italy have chose to go on strike following their largest shareholder's decision to spend a whopping £99.2m for the transfer of Cristiano Ronaldo to Juventus.
The workers plan to strike at the plant in Melfi, Italy, between Sunday and Tuesday, according to Bloomberg.
Liverpool FC finished in fourth place in the Premier League table last season as they secured Champions League qualification for next season.
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And the Liverpool defender has praised Croatian parents for "making good love" and giving the small country several sports stars. They are a strong team, their players play all over the world. "I'm happy for them of course".
The 23-year-old also started all three of Serbia's group stage games at this summers World Cup finals and his potential has caught the attention of some top clubs with Manchester United and Real Madrid among those to have expressed an interest in signing Milinkovic-Savic.