W&G Investments Plc , one of the three bidders vying for Royal Bank of Scotland's 315 branches, said the sale could be delayed beyond the two-year schedule.
RBS has been ordered to sell the branches in return for receiving a 45.5 billion pound ($71.04 billion) bailout during the 2008 financial crisis which left British taxpayers owning 81 percent of the bank. The sale process dubbed Project Rainbow, suffered a setback in October when Santander pulled out of a deal to buy the branches for 1.65 billion pounds.
"It is possible that separation will not be achieved within the two-year period currently contemplated by RBSG," W&G Investments, which will list on the London Stock Exchange on Monday, said in a regulatory filing while listing risk factors to the possible deal.
W&G Investments said the proposed deal was a complex and time consuming process.
W&G Investments led by former Tesco finance director Andy Higginson; a consortium including private equity firms Corsair Capital and Centerbridge; and a group led by Anacap Financial and Blackstone are bidding for the state-backed bank's branch network.
W&G Investments said the overall consideration for the deal had yet be agreed upon. However, if successful, it would pay 1.1 billion pounds in cash up front.