TOKYO, Dec 17 (Reuters) - Japanese financial services group Orix Corp (8591.T) said on Friday it will sell software developer Yayoi Co to U.S. private equity firm KKR & Co Inc (KKR.N) for an undisclosed amount. Orix, which bought Yayoi for more than 80 billion yen ($705 million) in 2014, will complete the transaction in March and book a profit of 163.2 billion yen ($1.44 billion) from the sale in the January-March quarter. Yayoi is a major financial and accounting software provider for Japanese small- and medium-sized firms, best known for its namesake accounting and tax filing software. It had sales of 21 billion yen in the financial year ended in September. ($1 = 113.5500 yen)