Former Birmingham owners David Gold and David Sullivan have tabled a £50million takeover bid, which is understood to be around half the club's own valuation.

Gold and Sullivan are reportedly ready to provide manager Gianfranco Zola with a £20million January transfer fund to improve a squad currently struggling to escape the Barclays Premier League relegation zone.

CB Holding have told the West Ham board they are in talks with a number of interested parties - but stressed they are under no pressure to rush into any deal.

The investment bank's financial position was strengthened on December 11 when the District Court of Reykjavik granted their parent company Straumur Bank a moratorium on their debts until September.

In a club statement, West Ham said: "Our shareholder CB Holding has made it clear it would like to find new owners for the club in the next three years and that is still the case.

"In recent months we have had a number of approaches from parties interested in investing in West Ham United.

"The club have held a number of discussions with those parties and talks are still ongoing.

"CB Holding is not under pressure to conclude an agreement in the immediate future, but the club will keep supporters informed of any developments when appropriate."

West Ham's current financial predicament has led to suggestions that England quartet Rob Green, Matthew Upson, Scott Parker and Carlton Cole may have to be sold in the transfer window.

Zola is desperate to keep that spine of his squad together but the Italian does not know what January will bring - and he admits a final decision may ultimately be out of his hands.

"You know, we want to keep the best players. I don't know what's going to happen next month," said Zola.

"The only thing I know for sure is that before then we have three games coming up that are very, very important and I want to focus on them. That's the main thing, the rest is out of my control."

The Hammers tackle Portsmouth, the only side below them in the league, on Boxing Day followed by high-flying Tottenham on December 28 and Arsenal in the FA Cup on January 3.

West Ham may be in 19th place but they head into the Portsmouth game on the back of a 1-1 home draw with league leaders Chelsea.

"The first step is get through this game on Saturday which is vital and let's do it all together and then we'll see what happens (in January)," Zola added.

"I can only focus on the game and make sure everything goes well on the pitch. If we keep the same spirit we have against Chelsea I think we are going to go through everything, that is my personal belief."

Defender Danny Gabbidon will miss the Portsmouth game with a hamstring injury but Zola has midfielder Valon Behrami back in contention.