GERMAN firm Siemens is working on a formal asset-swap offer for Alstom's power business.
And details of its bid, which could also see the French government take a stake in the remaining Alstom rail business, could come within days, according to speculation this week.
Alstom, which has a major centre in Stafford, is already in talks with giant US firm General Electric over a bid for its power business, with an announcement on progress due by June 2.
But Alstom has also opened its books to Siemens to give the rival bidder the opportunity to put forward its own deal, following pressure from the French government.
The Siemens asset swap offer could involve it taking over all Alstom's power business in exchange for handing over its own rail undertakings.
There are also suggestions that Siemens could offer to sell Alstom's wind and nuclear power assets to state-controlled energy group Areva.