Tenon employs 220 people across five offices in Scotland, but The Herald revealed earlier this week that its five Glasgow partners had resigned to start their own venture, adding to doubts over the company's future.
The combined headcount of the two businesses in Scotland is more than 300.
Deloitte said no job losses were expected in the proposed sale of the trading entities, but a Baker Tilly spokesman said there would be an integration review, adding: "Until that review is complete, we can't give any firm indications."
He added that the value of the deal had not yet been disclosed. Tenon said: "The terms of the sale agreement mean that Lloyds will not recover its secured debt in full."
Tenon broke the mould of traditional partner-owned accountancy firms, which are not known to become insolvent.
It was named "national firm of the year" at the British Accountancy Awards 2011, despite having had to restate its own accounts in January 2011, triggering the resignation of chief executive Andy Raynor and chairman Bob Morton, who had driven its aggressive buy-and-build strategy.
They raised £40m to acquire Tenon's midmarket rival RSM Bentley Jennison for £76m in 2010, moved the group's shares to the main market, and promoted RSM Tenon as "the largest commercial provider of bankruptcy services in the UK".
Now the shareholder wipe-out, predicted by The Herald on August 5, has crystallised big losses for Mr Morton, who had 7% of the shares, and fund group Jupiter with 8%. Hedge fund guru Crispin Odey was left holding a 5.8% stake, despite reducing his position marginally when the shares were at 1.76p.
Tenon's shares were at 66p in early 2011 but had slid to 6p before Baker Tilly said on July 25 it was mulling an offer.
The collapse came after Baker Tilly exhausted its 28-day diligence period by declaring at 7am yesterday that it would not make an offer - but was "interested in an alternative potential transaction". At 7.30am, Tenon's shares were suspended at 1.12p, and just after 10am, Tenon announced that it had called in administrators after Lloyds had "informed the company this morning that, should the company, as expected, be in breach of its banking covenants, it would not be willing to grant a covenant waiver".
Matt Smith of Deloitte said: "Immediately following our appointment, a sale of RSM Tenon Group plc's trading subsidiaries to Baker Tilly was agreed."
He went on: "We believe the proposed sale to Baker Tilly represents the best outcome for the RSM Tenon group.
"The management of the group have stabilised the business, returning it to profitability over the past 18 months and making this transaction possible to secure its future.
"In the meantime, we are working closely with the directors of the trading entities and their management and staff to continue to support the business until the sale is completed. We appreciate the cooperation and support from the staff, customers, suppliers and landlords during this period."
Tenon had warned on July 25 that any offer might be below the current share price and last Monday it said the value put on the shares might be "minimal, if any".
Last February it had admitted there was a "significant risk of a facility breach" over the next 12 months on its £80.4m of debt to Lloyds.
RSM Tenon is the seventh largest accountancy and business advisory firm in the UK, employing around 2500 across 38 offices, with revenues understood to be now similar to Baker Tilly's £170m, on which the privately-held firm makes around £12m of profit.
Tenon had installed Chris Merry as chief executive in an attempt to pull the business round, but on a visit to Scotland in March, Mr Merry was notably cautious on the company's prospects for survival.
He said: "As a public company, we have to look forward 12 to 15 months as a going concern, but we have done that in the context of Lloyds being extremely supportive."