Martin Gilbert’s AssetCo acquisitions vehicle is expected to formally lodge its offer for River and Mercantile this week following the withdrawal of a rival bidder.

Premier Miton dropped out of the race last week, leaving the field open for AssetCo with a clear run to bid for R&M in which it already owns just under 6% of the shares. The Takeover panel gave both firms an extended deadline of 18 January to make their intentions clear.

Mr Gilbert, co-founder of Aberdeen Asset Management and former chief executive of Standard Life Aberdeen, is deputy chairman of R&M and there is some operational overlap.

Last week, Premier Miton chief executive Mike O’Shea confirmed his company was withdrawing its interest and said: “We are most grateful to the board of RMG for their co-operation and assistance as we have assessed the merits of a possible transaction, especially so given the major changes ongoing in their business.”

Both bids were contingent on the sale of R&M’s fiduciary business to Schroders, which has since been successfully concluded.

Mr Gilbert is keen to build AssetCo into a new asset manager through consolidation and last May acquired Edinburgh-based Saracen Fund Managers in a cash and shares deal worth £2.75 million.