Apollo Global Management Inc. is in talks with Soft Bank Group Corp. about boosting the size of a loan to $9 billion from $5.4 billion to help the Japanese firm amplify its bets on AI giant Open AI. The size of the financing, which is backed by assets in Soft Bank's Vision Fund 2, hasn't been finalized, the people said, requesting not to be identified because the discussions are private. Representatives for Apollo and Soft Bank declined to comment.