W I L L I A M S T R E E T William Street Commitment Corporation / 1 New York Plaza/New York, NY 10004

Exhibit 99.11

X X X X X X X    S T R E E T

Xxxxxxx Street Commitment Corporation / 0 Xxx Xxxx Xxxxx/Xxx Xxxx, XX 00000

December 22, 2006

Aetna Inc.
000 Xxxxxxxxxx Xxxxxx
Xxxxxxxx, XX 00000

Re: Amended and Restated Five-Year Credit Agreement dated as of January 20, 2006 (the “Credit Agreement”)

Attention: Xxxxxx X. Xxxxx, Vice President, Finance and Treasurer

Dear Al:

We have received your Extension Request, dated December 5, 2006, and pursuant to Section 2.06(c) (Maturity of Loans) of the above-referenced Credit Agreement, we hereby agree to the extension set forth in such request. Upon the effectiveness of the Extension Request in accordance with Section 2.06(c) of the Credit Agreement, the new Maturity Date will be January 20, 2012.

We have made a notation of this extension on the Schedule of Loans, Payments of Principal attached to our Syndicated Note(s).

Very truly yours,

XXXXXXX STREET COMMITMENT CORPORATION
(Recourse only to assets of Xxxxxxx Street Commitment Corporation)

By:		/s/ Xxxx Xxxxxx
Xxxx Xxxxxx
Assistant Vice President
Telephone Number: (000) 000-0000