By Rick HowlettThe chairman of PPL Corporation is calling his company's pending purchase of Louisville Gas and Electric Company and Kentucky Utilities a transformational event. James Miller says the acquisition will bring together three of the best utility companies in the United States and turn PPL into a more geographically diverse operation."Most importantly, it rebalances our business mix. it does it in one step. It improves our financial stability, it improves our credit profile, Miller told reporters in a conference call Thursday morning.He says with the purchase, Pennsylvania-based PPL will serve nearly five million electricty customers in the U.S. and Great Britain. The sale is expected to become final at the end of the year.