ArcLight Capital Partners and Kelso & Co. are planning a $17 per unit tender offer for all outstanding common units they do not already own of pipeline operator Buckeye GP Holdings LP (NYSE: BGH). The two firms – along with Lehman Brothers – bought a 63% stake in Buckeye from Carlyle-Riverstone last year. Lehman Brothers was not mentioned in the announcement. www.buckeye.com