Details of the deal, which will bring to an end a running feud lasting well over a year, are being kept completely confidential.
The only information on the agreement comes in a curt statement issued by the board yesterday. This states: 'The court proceedings between the ARB and Ian Salisbury have been settled on terms satisfactory to both parties.
'It has been agreed that the terms will remain confidential and that neither party will make any comment about the proceedings or the terms of settlement beyond this press release,' it finishes.
The deal, whatever form it takes, marks the end of a chapter in the board's history that its senior members, such as the chair Humphrey Lloyd, will be keen to forget.
They have been in a long and damaging dispute with Salisbury, who, as a maverick member of the organisation's board, challenged much of its received wisdom.
However, as one battle ends, another begins. The board is facing the possibility that all seven seats reserved for members of the profession could be taken at the forthcoming election by the ARB Reform Group, an organisation that shares many policies with Salisbury.