This will be welcome news to Jones who has to replace Danny Gabbidon and James Collins who both left to join West Ham this week.
Hammam said on the club's website: "At this point £2.5m of funds received will be set aside to make sure we can go through the 2005-06 season without further financial problems.
"The balance will be made available to the manager to improve the team. We cannot announce the transfer fee for Gabbidon and Collins because of a confidentially agreement with West Ham.
"There is the possibility of further payments linked to West Ham's future in the Premiership.
"But one small but nonetheless bright note is because when we buy players it's on instalments, so the manager might be able to buy far more than the £600,000 he has available."