(Reuters) - Britain's Arbuthnot Banking Group Plc (L:ARBB) said it would sell about 5.8 million shares, or a 31.9 percent stake, in its retail bank Secure Trust Bank Plc (L:STBS) through a secondary placing.
Shares in Arbuthnot were up 6.9 percent at 1550 pence on the London Stock Exchange, while Secure Trust's shares were down 8.9 percent at 2550 pence.
Secure Trust is one of a number of new banks seeking to gain market share from the UK's four biggest lenders - Lloyds Banking Group Plc (L:LLOY), Royal Bank of Scotland Group Plc (L:RBS), Barclays Plc (L:BARC) and HSBC Holdings Plc (L:HSBA).
Arbuthnot, which has its roots in 183-year-old private bank and wealth manager Arbuthnot Latham, said it expected to sell the shares at about 25 pounds per share to institutional investors, generating about 145 million pounds in cash.
Arbuthnot's stake in the retail bank will fall to about 20 percent from 51.9 percent earlier after the sale.