**Exhibit 12.1**

**CERTIFICATIONS**

I, Fred Kindle, certify that:

1.                 I have reviewed this annual report onForm 20-F of ABB Ltd;

2.                 Based on my knowledge, this report does notcontain any untrue statement of a material fact or omit to state a materialfact necessary to make the statements made, in light of the circumstances underwhich such statements were made, not misleading with respect to the periodcovered by this report;

3.                 Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of the company as of, and for, the periods presented in thisreport;

4.                 The company’s other certifying officer and Iare responsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e))and internal control over financial reporting (as defined in Exchange Act Rules13a-15(f) and 15d-15(f)) for the company and have:

(a)             Designed such disclosure controls andprocedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating to thecompany, including its consolidated subsidiaries, is made known to us by otherswithin those entities, particularly during the period in which this report isbeing prepared;

(b)            Designed such internal control over financialreporting, or caused such internal control over financial reporting to bedesigned under our supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financial statementsfor external purposes in accordance with generally accepted accountingprincipals;

(c)             Evaluated the effectiveness of the company’sdisclosure controls and procedures and presented in this report our conclusionsabout the effectiveness of the disclosure controls and procedures, as of theend of the period covered by this report based on such evaluation; and

(d)            Disclosed in this report any change in thecompany’s internal control over financial reporting that occurred during theperiod covered by the annual report that has materially affected, or isreasonably likely to materially affect, the company’s internal control overfinancial reporting; and

5.                 The company’s other certifying officer and Ihave disclosed, based on our most recent evaluation of internal control overfinancial reporting, to the company’s auditors and the audit committee of thecompany’s board of directors (or persons performing the equivalent functions):

(a)             All significant deficiencies and materialweaknesses in the design or operation of internal control over financialreporting which are reasonably likely to adversely affect the company’s abilityto record, process, summarize and report financial information; and

(b)            Any fraud, whether or not material, thatinvolves management or other employees who have a significant role in thecompany’s internal control over financial reporting.

Date:  April 18, 2007
| /s/ FRED KINDLE          |   |
|--------------------------|--------|
| Fred Kindle              |
| Chief Executive  Officer |

 

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