Exhibit 23-a CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this registration statement (No. 333-92003) of our report dated February 12, 1999 included in KeySpan Corporation's form 10-K for the nine months ended December 31, 1998. /s/ Arthur Andersen _________________________ ARTHUR ANDERSEN LLP January 19, 2000 New York, New York