A French businessman who sold tens of thousands of breast implants filled with industrial-grade silicone and prone to leaks was convicted of fraud on Tuesday and sentenced to the maximum four years in prison.

The lawyer for Jean-Claude Mas, who founded Poly Implant Prothèse (PIP), the company that made the faulty implants, promised to appeal immediately, disappointing the dozens of women who travelled to the courthouse in Marseille hoping to see Mas hauled away to prison.

However, in a decision that could affect thousands of women worldwide who have sought financial reparations, the court also ruled that the German product-testing company TUeV Rheinland, which cleared the PIP implants for certification, was also a victim of Mas's deception, which officials said included falsified paperwork and a shadow production line.

It was not immediately clear how Tuesday's verdict affects a decision in a Toulon commercial court last month that ordered TUeV to pay damages to more than 1,600 women and six distributors for the implants.

Product-testing firm denies responsibility

The PIP implants were filled with industrial-grade silicone — instead of medical grade — and were prone to leak. Around 125,000 women underwent plastic surgery with PIP implants.

Mas, a former Bristol Myers sales representative, has since dissolved the company. Because PIP is bankrupt, the 5,000 women who have joined a complaint against the French company are unlikely to retrieve much compensation. But TUeV, a leader in the industry that was charged with checking the quality of the implants, has deep pockets.

TUeV denies responsibility and has promised to appeal the commercial court ruling, which opens it to the possibility of at least 50 million euros ($67 million US) in damages — about 3,000 euros per woman, lawyers say.

"We got sick, and then they told us it's not the silicone's fault. But it was — it was the silicone's fault," said Martine Favret, who wore a red brassiere over her white t-shirt as a symbol of what she described as her "revolt."

Implants sold in several countries

PIP once claimed its factory in southern France exported to more than 60 countries and was among the world's top implant makers. According to government estimates, more than 42,000 women in Britain received the implants, more than 30,000 in France, 25,000 in Brazil, 16,000 in Venezuela and 15,000 in Colombia.

'We have these inside us. If we want them gone, we have to undergo surgery. - Martine Favret

Sales of the implants ended in March 2010. After the first reports emerged of implants rupturing, regulators across Europe tightened oversight of medical devices.

Favret, like many of the women, called for more oversight of an industry they say could be prone to cutting corners.

"This is more dangerous than a medication that you can just stop taking," she said. "We have these inside us. If we want them gone, we have to undergo surgery. We have to stop protecting these giant industries just for cash. Cash is good, but health is better."

Women still living with leaky implants

Mas acknowledged problems with PIP but said he never intended any harm. Defence lawyer Yves Haddad said the pressure to convict was intense.

"Four years is the maximum allowed by the law," Haddad said outside the courthouse, after promising an appeal. "I fear that the pressure on the court was too great."

PIP implants

The silicone gel breast implants made by the French company Poly Implant Prothèse (PIP0, above, were made with industrial silicone rather than medical silicone and were prone to ruptures. (Michel Euler/Associated Press)

Jan Spivey, who received implants after undergoing a mastectomy for breast cancer in 2002, said she was vindicated by Tuesday's ruling. For years, the British woman said, she could not understand why, even with her cancer gone, she was still sick. Then, when the reports about PIP emerged in 2011, she knew.

She said the hospital confirmed that her implants were seeping silicone.

"Many many women are still living with ruptured PIP in Britain, which I think is completely unacceptable," she said. "Women have got to be respected. They should have their dignity, and they should have been treated accordingly from the beginning."

She was taken aback when she learned that Mas would remain free on appeal.

"I thought he was going to be taken away in a vehicle today, and we wouldn't see him again," she said.