SINGAPORE, Aug 19 (Reuters) - Indonesia"s biggest tech group GoTo is set to complete a pre-IPO funding exercise to raise up to $2 billion in the next few weeks, but regulatory delays threaten to push its listing plans to early next year, three sources familiar with the matter said. The delay comes as the southeast Asian nation"s Financial Services Authority (OJK) weighs new listing guidelines for tech firms to offer dual-class shares that confer different voting rights, said two of the sources. All the sources sought anonymity as they were not authorised to speak to the media. A spokeperson for GoTo declined comment while there was no immediate comment from the regulator, OJK.GoTo, formed through the merger of ride-hailing-to-delivery-to-payments firm Gojek and e-commerce leader Tokopedia in May, was targeting to list in Indonesia by year-end, followed by a U.S. listing, with a potential valuation of about $40 billion. However, delays to a proposed revamp of Indonesia"s listing rules, now expected to be unveiled late in September, mean GoTo is only likely to launch its IPO early next year, followed by the U.S. listing. One of the sources said the effort to raise funds of $1.5 billion to $2 billion ahead of the IPO exercise drew strong demand, and could be completed next month. GoTo, backed by investors such as Alibaba Group Holding (9988.HK), Softbank Vision Fund and Singapore wealth fund GIC, is among the companies benefiting from greater use of digital platforms by consumers stuck at home by pandemic lockdowns. The surge in investor interest helped e-commerce firm Bukalapak.com (BUKA.JK)to raise $1.5 billion last month in Indonesia"s biggest IPO. But since its listing this month, shares of Bukalapak have shed about 30% from record highs, to close on Thursday at just 5% above the IPO price of 850 rupiah. ($1 = 14,400.0000 rupiah)