NEW YORK STOCK EXCHANGE, INC. 11 Wall Street 6th Floor New York, New York 10005

Exhibit 99.1

NEW YORK STOCK EXCHANGE, INC.
00 Xxxx Xxxxxx
0^xx Xxxxx
Xxx Xxxx, Xxx Xxxx 00000

December 2, 2005

General Atlantic Partners 77, L.P.,
GAP-W Holdings, L.P.,

GapStar, LLC,
GAP Coinvestment Partners II, L.P.,
GAPCO Gmbh & Co. KG

c/o General Atlantic Service Corporation

0 Xxxxxxxx Xxxxx

Xxxxxxxxx, Xxxxxxxxxxx 00000

Ladies and Gentlemen:

Reference is made to the Amended and Restated Support and Lock-Up Agreement, dated as of July 20, 2005 (the “Agreement”), by and among General Atlantic Partners 77, L.P., GAP-W Holdings, L.P., GapStar, LLC, GAP Coinvestment Partners II, L.P., and GAPCO Gmbh & Co. KG (together, “General Atlantic”), each in its capacity as a stockholder  of Archipelago Holdings, Inc., a Delaware corporation (“Archipelago”), and New York Stock Exchange, Inc., a New York Type A not-for-profit corporation (the “NYSE”).  Capitalized terms used and not defined herein shall have the respective meanings attributed to them in the Agreement.

Pursuant to Section 10 of the Agreement, the NYSE hereby waives Section 2(b)(i), clause (B) of Section 2(b)(ii) and Section 2(b)(iii) of the Agreement with respect to all of General Atlantic’s Shares.

Except as specifically set forth herein, NYSE expressly reserve all rights under the Agreement.

	Very truly yours,
	NEW YORK STOCK EXCHANGE, INC.
	By:	/s/ Xxxxxxx X. Xxxxxxx
	Name:	Xxxxxxx X. Xxxxxxx
	Title:	Executive V.P. and General Counsel

NEW YORK STOCK EXCHANGE, INC.
00 Xxxx Xxxxxx
0^xx Xxxxx
Xxx Xxxx, Xxx Xxxx 00000

December 2, 2005

Xxxxxxx Xxxxx Execution & Clearing, L.P.
GS Archipelago Investment, L.L.C.

SLK-Hull Derivatives LLC

c/o The Xxxxxxx Xxxxx Group, Inc.

00 Xxxxx Xxxxxx

Xxx Xxxx, Xxx Xxxx 00000

Ladies and Gentlemen:

Reference is made to the Amended and Restated Support and Lock-Up Agreement, dated as of July 20, 2005 (the “Agreement”), by and among GS Archipelago Investment, L.L.C., SLK-Hull Derivatives LLC and Xxxxxxx Xxxxx Execution and Clearing, L.P. (together, “Xxxxxxx Sachs”), each in its capacity as a stockholder  of Archipelago Holdings, Inc., a Delaware corporation (“Archipelago”), and New York Stock Exchange, Inc., a New York Type A not-for-profit corporation (the “NYSE”).  Capitalized terms used and not defined herein shall have the respective meanings attributed to them in the Agreement.

Pursuant to Section 10 of the Agreement, the NYSE hereby waives Section 2(b)(i), clause (B) of Section 2(b)(ii) and Section 2(b)(iii) of the Agreement with respect to all of Xxxxxxx Xxxxx’ Shares.

Except as specifically set forth herein, NYSE expressly reserve all rights under the Agreement.

	Very truly yours,
	NEW YORK STOCK EXCHANGE, INC.
	By:	/s/ Xxxxxxx X. Xxxxxxx
	Name:	Xxxxxxx X. Xxxxxxx
	Title:	Executive V.P. and General Counsel

NEW YORK STOCK EXCHANGE, INC.
00 Xxxx Xxxxxx
0^xx Xxxxx
Xxx Xxxx, Xxx Xxxx 00000

December 2, 2005

GSP, LLC
Archipelago Holdings, Inc.
ATTN: Legal Department
000 Xxxxx Xxxxxx Xxxxx

Xxxxx 0000
Xxxxxxx, Xxxxxxxx 00000

Ladies and Gentlemen:

Reference is made to the Amended and Restated Support and Lock-Up Agreement, dated as of July 20, 2005 (the “Agreement”), by and between GSP, LLC (“GSP”), in its capacity as a stockholder  of Archipelago Holdings, Inc., a Delaware corporation (“Archipelago”), and New York Stock Exchange, Inc., a New York Type A not-for-profit corporation (the “NYSE”).  Capitalized terms used and not defined herein shall have the respective meanings attributed to them in the Agreement.

Pursuant to Section 10 of the Agreement, the NYSE hereby waives Section 2(b)(i), clause (B) of Section 2(b)(ii) and Section 2(b)(iii) of the Agreement with respect to all of GSP’s Shares.

Except as specifically set forth herein, NYSE expressly reserve all rights under the Agreement.

	Very truly yours,
	NEW YORK STOCK EXCHANGE, INC.
	By:	/s/ Xxxxxxx X. Xxxxxxx
	Name:	Xxxxxxx X. Xxxxxxx
	Title:	Executive V.P. and General Counsel