LONDON (Reuters) - Fifteen Lloyds Banking Group <LLOY.L> executives have bought almost a million of the lender's shares in a post-referendum show of confidence in Britain's economic prospects after the country voted to leave the European Union on Friday.A total of about 829,000 shares in the state-backed bank were bought at an average price of about 55.8 pence in 17 transactions on Wednesday, according to a regulatory filing.

"The purchases were personal decisions for the executives, and reflect confidence in the Group's business model," a Lloyds spokesman said.

The approximate value of the shares purchased was about 463,000 pounds ($621,068), according to a Reuters calculation.

An additional 105,872 of shares were acquired by members of the board and senior staffers, the filing said.

Like other bank stocks, shares in Lloyds, the UK's largest mortgage lender and a key provider of British consumer and company finance, plunged in the days immediately after the historic vote but have recovered some ground since.

Shares were trading at 53.7 pence at 1312 GMT on Thursday, compared with the government's 73.6 pence so-called 'break-even' price.

Chief Executive Antonio Horta Osorio also used the downturn to add to his shareholdings, after purchasing 100,000 shares at a price of 54.2 pence on Tuesday.

(Reporting By Andrew MacAskill and Sinead Cruise; Editing by Elaine Hardcastle)