The transaction of the 17 million shares was completed on Jan 18, according to a statement to the Stock Exchange of Thailand.
The shares were sold by Charoen Pokphand Group Co Ltd, Charoen Pokphand Foods Plc and Bangkok Produce Merchandising Plc.
AYUD will see its stake in AACP rise above 11 per cent after the transaction.
As of Dec 30, 2011, the three sellers owned a combined stake of 7.24 per cent in AACP.
AACP, an insurance firm, has shown an improvement in earnings in the past few years. It registered a net profit of Bt571.66 million in the first nine months of 2011.