A consortium has offered £520 million to buy recycling and waste business Biffa, according to a report in The Guardian newspaper.
It reports that current owners Montagu Private Equity and Global Infrastructure Partners have received a bid from a consortium including Chinook Urban Mining, private equity investor Clearbrook Capital and US bank JP Morgan.
Other debt funds are believed to be circling Biffa, although none have made an offer yet.
Biffa was bought by its current owners for £1.2 billion in 2008, but this investment has now been written off.
The consortium that has made the bid is understood to want to transform Biffa by implementing more waste to energy technology in order to return it to profitability.
In the year to April 2011, Biffa made a pre-tax loss of £127.5 million on revenues of £775.1 million.