KUALA LUMPUR, Aug 6 (Reuters) - South Korea"s SK Group (034730.KS) will invest up to $100 million in the financial technology unit of AirAsia Group Bhd (AIRA.KL), the Malaysian budget carrier said in a statement on Friday. BigPay, a unit of AirAsia"s digital arm, offers a prepaid debit card, local and international money transfers, micro-insurance, bill payments and a budgeting tool. "Our ambition has always been to establish BigPay as one of the largest challenger banks in Southeast Asia," said Salim Dhanani, the company"s chief executive officer, who added that BigPay plans to expand into Thailand and the rest of the region with personal loans and short-term lending. "Closing this financing round gives us the ability to build out our offerings, accelerate product development and scale," he said. BigPay has also applied for a digital banking licence in Malaysia as part of a consortium with Malaysian Industrial Development Finance Berhad and private equity firm Ikhlas Capital. SK Group said it would "make a significant contribution to BigPay in both technical and consumer service aspects," according to the statement. AirAsia has suffered from the pandemic slump in global travel and has been pushing to grow its digital businesses, which include a logistics firm and a travel and lifestyle services app. On Thursday, the airline said it had netted $56.83 million from a merger between Fly Leasing Limited and Carlyle Aviation Partners, and was working on a data-backed loan of up to $350 million.