Listing costs weren't mentioned in Sanyo's press release but a Nikkei Shimbun article mentioned cost savings and a lesser burden on its operations by having to maintain listings on fewer exchanges as motivating factors.
Sanyo will continue to trade on the Tokyo and Osaka stock exchanges and although it has "made no arrangements to list its ADSs on another U.S. exchange" the Nikkei article said it will continue reporting its financials per SEC requirements. It expects the delisting process to be completed by this December.
Its ordinary shares (Tokyo: 6764) gained 3.33% on the day to close at 248 yen ($10.59 ADS equivalent) as the delisting decision was viewed as a positive move amidst the firm's restructuring to further contain costs and likely enhance liquidity of already very liquid trading of its shares in Tokyo.
Its ADSs closed yesterday at $10.26. Trading volume is typically under 10,000 shares traded per day but there will likely be an increase ahead of its delisting.