Widnes chairman Steve O'Connor has pledged £10,000 to boost the survival hopes of Super League rivals Bradford.
A total of £155,000 has so far been pledged to the Bulls, who say they need £500,000 by 6 April to pay a tax bill and avoid the threat of administration.
"Steve rang to offer his support and wanted to pledge a sum of £10,000," said Bulls chairman Peter Hood.
"He spoke eloquently at length about the rugby league community and how we are all in this together."
Hood added: "Steve talked of the outstanding contribution that the Bradford Bulls have made to the game and he wants that to continue.
"His heartfelt and extremely generous contribution epitomises the response we have had from [people] throughout the game."
More than £100,000 was pledged to Bradford inside the first 48 hours after their financial plight came to light, with the club targeting a figure of £1m by the end of April to guarantee their survival.