Atel Capital Equipment Fund Xi 10-Q 2009 Q2 Quarterly report

Exhibit 32.1

CERTIFICATION PURSUANT TO 18 U.S.C. §1350,

AS ADOPTED PURSUANT TO

§906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of ATEL Capital Equipment Fund XI, LLC (the “Company”) on Form 10-Q for the period ended June 30, 2009 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Dean L. Cash, President and Chief Executive Officer of ATEL Financial Services, LLC, Managing Member of the Company, hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that:

1. The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: August 12, 2009

/s/ Dean L. Cash

Dean L. Cash

President and Chief Executive Officer of ATEL Financial Services, LLC (Managing Member)

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.