Charge card issue Diners Club has reported a fall in revenue and profit for the year to December, but Diners' owner Citibank says the fall in income in the financial report is the result of an inter-company transaction and not a deterioration in the performance of the business.The Diners Club financial report for its local operation shows a fall in revenue from A$45.6 million in 2014 to $41.2 million last year, and a fall in earnings from $5.6 million to $2.3 million.Citi head of cards and consumer lending Alan Machet said the financial report did not show the impact of internal funding on income.Machet said cardholder spend year-on-year was roughly flat.He said Diners had invested in its "points of presence" and increased the number of merchants accepting Diners charge cards by around 20 per cent last year.The business is focused on issuing to corporate and government customers, with less emphasis on consumers. Machet said that focus was maintained last year with issuance numbers also roughly flat.Diners Club is classified as a three-part scheme for regulatory purposes. Last October the Reserve Bank designated some parts of the American Express business, also a three-party scheme, putting it under its interchange pricing rules.Machet said the American Express Companion Card payment system was designated (Amex cards issued by banks) and not Amex charge cards.Diners has not been affected by the change in RBA card regulation.