Mercer is also remembered for his attempt in 1990 to merge the two major Edinburgh clubs, Hearts and Hibs. Mercer reasoned that the Old Firm had far greater financial power than either Edinburgh club and that the only way to realistically compete was with a united Edinburgh club. Hibs fans suspected that the "merger" was more of a takeover by Hearts and they strongly resisted Mercer's bid to acquire a majority share in Hibs. Mercer was eventually forced to abandon his plans as some key shareholders refused to sell to him, denying him the level of shareholding needed to liquidate Hibs. Sir Tom Farmer eventually took financial control of Hibs instead.
In 2010, Mercer's widow and children issued a statement to the Edinburgh Evening News reiterating the reasons for the proposed merger of Hearts and Hibs. The statement also claimed that the increased dominance of the Old Firm since 1990 had vindicated the proposal.
- Paterson, Liam (17 January 2006). "Wallace Mercer dies". The Scotsman. Retrieved 21 February 2011.
- "Mercer Merger - 20 years on: Wallace Mercer decides to call it quites as David Duff digs in". Edinburgh Evening News. 4 June 2010. Retrieved 21 February 2011.
- Hardie, David (4 June 2010). "Wallace Mercer's Hearts/Hibs merger vision 'proved right'". Edinburgh Evening News. Retrieved 21 February 2011.
- "Mercer applause tribute for derby". BBC Sport. 18 January 2006. Retrieved 21 February 2011.
- Picken, Andrew (25 January 2006). "Hibs fans to turn backs on derby day Mercer tribute". Edinburgh Evening News. Retrieved 21 February 2011.
- Grant, Michael (29 January 2006). "Derby debut gives Rix reason to believe". Sunday Herald. Retrieved 21 February 2011.