EXHIBIT 99.(c)(1) PURCHASE AGREEMENT BY AND AMONG COLUMBIA PROPANE L.P., CP HOLDINGS, INC., COLUMBIA PROPANE CORPORATION, NATIONAL PROPANE PARTNERS, L.P., NATIONAL PROPANE CORPORATION, NATIONAL PROPANE SGP, INC.Purchase Agreement • April 9th, 1999 • Columbia Energy Group • Natural gas transmisison & distribution • Delaware
