A host of charges against accountancy firm Deloitte over its role in the collapse of UK carmaker MG Rover have been thrown out.

Eight of the 13 charges against the firm related to transactions with the Phoenix Four before the car giant collapsed have been overturned on appeal.

Deloitte is now expected to see a reduction in its record £14 million fine imposed by the accountancy industry regulator for misconduct.

Its accountants advised the Phoenix Four and it was also the MG Rover auditor during a period when the directors extracted more than £40 million in financial rewards from the firm.

The appeal threw out all six charges in relation to a transaction called Project Aircraft and two relating to a second transaction, called Project Platinum. However, the remaining five charges were upheld and the appeal tribunal was critical of Deloitte's client engagement processes.

Northfield MP Richard Burden described the latest ruling as a "damning verdict" and also repeated a call for any new fine levied to go to benefit former MG Rover workers, rather than to the Institute of Chartered Accountants.

Related: Comment - MG Rover workers still owed a payout years after this sorry saga

MG Rover collapsed into administration in 2005 with debts of £1.4 billion and more than 6,000 job losses.

A spokesperson for Deloitte UK said: "We are pleased that the findings of failing adequately to consider the public interest and deliberate serious misconduct have been overturned.

"We take such responsibilities extremely seriously and these findings were entirely unreflective of the integrity and values of our firm. However, we accept the tribunal's findings that aspects of our client engagement processes could have been better.

"As part of the continuous review of our internal guidelines, which have been strengthened regularly in the 14 years since this project, we will consider whether any further action is required."

The appeal related to a case in 2013 when Deloitte was fined £14 million by the Financial Reporting Council (FRC) over "persistent" failings in its dealings with MG Rover.

In September that year the FRC fined and severely reprimanded the accountant after ruling it did not spot conflicts of interest in its advice to MG Rover and directors who bought the company before its failure.

The FRC said two flawed deals in 2001 and 2002 benefited the Phoenix Four rather than MG Rover, and also earned Deloitte hefty fees.

Deloitte appealed the tribunal result, where the FRC found against Deloitte on 13 allegations, including failing to properly consider the public interest.

The FRC appeal tribunal upheld five of the findings of misconduct in relation to Deloitte's work on Project Platinum, the project to dispose of the MG Rover loan book, but overturned eight findings, including those in relation to Project Aircraft, which aimed to realise the value of tax losses within MG Rover Group.

Mr Burden said: "However they may try to spin it, this is still a damning verdict on Deloitte's involvement in the story of the Phoenix Four and MG Rover.

"There are parts of this judgement that should give everyone pause for thought about the rules and expectations governing corporate finance in this country."