Hundreds of workers at one of Australia's largest textile companies, the Bradmill Undare Group, were celebrating on Wednesday after a US investor bought the group's denim and spinning operations, Bradmill Textiles.

The sale to William "Sonny" Van Haselen means almost half the company's 850 jobs have been saved - 10 months after their future was thrown into turmoil by the company's shock collapse with debts of up to $100 million

A United States investor has bought out Bradmill Textiles, the group's denim and spinning operations, signing a revolutionary deal with unions to ensure workers' entitlements would never be put at risk again.

Receiver Mark Mentha said the new buyer would give Bradmill long term viability and that the unions had agreed a pioneering deal to ensure employees' entitlements would never be put at risk again.

"The key to Bradmill's future was the North American market, it was the missing link," Mr Mentha said after announcing the sale outside the Bradmill premises.

"We've got sales into Europe, we've got sales into south east Asia, we've got sales into Canada, but America was missing, this will fundamentally change Bradmill for the long term."

He added: "What we've done is mitigated a lot of those creditors through saving jobs, in realising assets for full value.

A spokesman for the Textile Clothing and Footwear Union (TCFU) said the majority of the redundancies had been voluntary and that as part of the deal Mr Van Haselen had agreed to a new agreement that ensured workers and their entitlements were protected.

Mr Van Haselen said he had plans to expand and upgrade the denim operations and was looking to pump $15 million into the company over the next two years.

Bradmill Textiles is the last division of the Bradmill Undare group to be sold following the sale earlier this year of the Pelaco, Bradmill Outdoor and Yarraville Textiles operations. The group's dyehouse which employed 175 people before it was closed is also expected to reopen in the near future.