A Scottish-led consortium was interested in a potential merger with the Dunfermline Building Society.
Financial services group Scottish Friendly Assurance said a consortium approached the stricken mutual in the middle of March, but was not given an opportunity to meet Dunfermline until Sunday - hours before a takeover deal was brokered with Nationwide.
The Glasgow-based company said face-to-face negotiations at an earlier stage could have resulted in a "Scottish-led solution" for DBS.
In a statement, Scottish Friendly Assurance said: "Scottish Friendly became part of a Scottish-led consortium that was interested in opening discussions with Dunfermline Building Society (DBS) regarding a potential merger.
"Initial approaches were made in the middle of March to DBS with Scottish Friendly joining the consortium shortly thereafter.
"Although numerous attempts were made to open exploratory negotiations with DBS, we were not given an opportunity to meet with them until Sunday March 29, less than 24 hours before a deal was announced.
"While we are of course pleased that the position of DBS members has been secured, the announcement of the deal with the Nationwide precludes a Scottish-led solution that may have been a possibility if talks had been agreed between the consortium and DBS at an earlier stage in this process."
Reckless lending led DBS to the brink of collapse with annual losses of more than £24m before the Government was forced to step in.
The Treasury paid £1.6bn to Nationwide as part of the deal, effectively as compensation for liabilities not covered by Dunfermline's assets.
Scottish National Party MP Stewart Hosie said all parties should have been aware of the possibility of alternative bidders before the Nationwide deal was struck.
