Paul Singer, founder and president of Elliott Management Corporation, speaks at WSJD Live conference in Laguna Beach Thomson Reuters (Reuters) - Elliott Management Corp, the largest creditor of the bankrupt parent of Oncor Electric Delivery Co, said it was in the process of making an offer that values the utility at about $18.5 billion, including debt.

Warren Buffet's Berkshire Hathaway last week offered $18.1 billion for the utility.

Elliott, run by billionaire Paul Singer, said in a letter to the board of Energy Future Holdings Corp, parent of Oncor, that any transaction other than one led by creditors would increase regulatory risks.

Elliott's bid would be a rare challenge to Berkshire Chairman Warren Buffett, who avoids auctions for companies and has told his investors he does not like to participate in bidding wars.

(Reporting By Aparajita Saxena in Bengaluru; Editing by Saumyadeb Chakrabarty)