lottery millionaires Colin and Chris Weir have launched a charity trust fund so they can make regular donations to good causes across Scotland.

The Weirs, who scooped the UK's largest-ever Euromillions jackpot of £161 million in July 2011, unveiled the Weir Charitable Trust as they appealed for individuals and organisations to apply for funding.

They have invested an initial £5m into the trust and will review bids for funding on a quarterly basis. The first deadline for applications is March 7, with awards announced in early April.

The Largs couple said: "We are delighted the Weir Charitable Trust is now open for business. Since we won the EuroMillions lottery, it has been a privilege to be in a position to provide support where we could.

"But we have been looking at finding a more structured way to share our good fortune on an ongoing basis across Scotland. It has taken some time to set up, but we are pleased the trust will now allow us to do that at a time when good causes in Scotland are struggling."

The venture is the latest example of generosity by the couple, which has seen them use their winnings to help friends and strangers alike.

They donated the £180,000 family home where they had been living at the time of their win to their neighbours after buying a luxury mansion, and sponsored 15-year-old Scottish racing driver Gregor Ramsey in the European and Italian Formula 3 events.

Mr Weir, a former Scottish TV cameraman, donated £750,000 to his local football team, Largs Thistle, to pay off some of the club's debt and improve facilities.

They also pledged £900,000 towards a new £1.2m multi-use sports arena in their home town and helped talented young artist Lee Craigmile pay his fees to study in Italy.

In August last year, they donated an unknown sum to help four-year-old Isabel Wallis from Musselburgh undergo life-changing surgery for cerebral palsy in the US.

The same month, the jackpot winners paid a five-figure sum to buy 13-year-old Kieran Maxwell, from Darlington, a new prosthetic limb. They had been touched after watching the teenager – who lost part of his leg to cancer – fall over as he carried the Olympic torch in the run-up to the London Games last year.

The SNP supporters also donated £1m to the party in September last year to support the campaign for independence.

Mr and Mrs Weir, a former psychiatric nurse, will run their trust along with two fellow trustees, solicitor Martin McLellan, of Kerr Barrie Solicitors, and RBS.

Lorraine Tait, administrator for the Weir Charitable Trust and responsible for its day-to-day management, said: "There is no minimum sum to be applied for – we are more concerned we reach groups, charities and individuals working hard in their communities, without mainstream support, who want to grow or who need funds to continue with their services."