Real estate investment trust Tritax Big Box said it expects to raise £54m by issuing 47,787,607 new ordinary shares at 113p each.The FTSE 250 group said the placing comprises the final tranche of its share issuance programme, which has raised approximately £339m since November.In a statement released on Thursday, the group added the net proceeds of the placing will be used to fund further investment in UK Big Box assets, which currently comprises of 22 assets with a valuation of approximately £1bn."We have been delighted by the response from existing shareholders and new investors to the company's share issuance programme and thank them for their support," said group non-executive chairman Richard Jewson.Tritax shares were up 0.09% to 113.00p at 08:47 on Thursday.