RSM Tenon, the bankruptcy advice specialists, yesterday ousted its chairman and chief executive, warned it might restate its own accounts, and appointed a turnround specialist, as it admitted slipping into losses.

The shares, 66p a year ago, fell 30% to 5.75p, as Tenon said Andy Raynor had stepped down as chief executive and left the group, while chairman Bob Morton would be replaced but stay on the board.

The acquisitive accountancy and advisory firm, which vies with Baker Tilly to be the UK's seventh- largest, employs 280 in Scotland, where 18 months ago Mr Raynor told The Herald he was ambitious to expand.

He said at the time Tenon drew only 10% of revenue from traditional audit which meant "we can stay ahead of the game".

RSM Tenon's trading in Scotland is said by observers to have been flat at best, prompting industry talk of a Scottish spin-out in a break-up of the firm.

A spokesman for RSM Tenon said: "A new management team has taken over today and they are going to evaluate and come up with a new strategy, nothing is sacrosanct and nothing has been decided."

The group, valued last night at £18.5 million, raised £40m to acquire mid-market rival RSM Bentley Jennison for £76m two years ago, and it picked up further assets from the administrators of Vantis in 2010.

RSM Tenon moved its shares to the main market and promoted itself as "the largest commercial provider of bankruptcy services in the UK and a close second in volume of corporate assignments".

Last month it issued a profits warning and warned of "limited headroom" in funding – it relies on an £80m facility from Lloyds Banking Group, which owns almost 10% of the shares.

The group reassured in December that it had been named "national firm of the year" at the British Accountancy Awards 2011, and that its market strength and core client base would drive growth, and it promised an update on February 21.

Yesterday, however, in an unscheduled update the group revealed revenues in its supposedly stronger second half were 10% down on the previous year.

It blamed "increased sensitivity to and pressure on pricing" and said transaction-based activities were "behind our expectations in a difficult economic environment". It now expects a first-half loss, even before amortisation of acquired intangibles, deferred consideration interest, and exceptional items, and said half the revenue decline was due to "updated accounting estimates".

The group has drafted in Jeremy Newman, former managing partner of rival BDO, as a consultant to help the board "improve significantly the performance and financial position".

The new executive chairman Adrian Martin said the board remained confident "that a successful turnaround can be delivered".