X0304 4/A 2010-11-22 2010-11-24 0 0000935494 NATIONAL INSTRUMENTS CORP /DE/ NATI 0001008357 KODOSKY JEFFREY L C/O NATIONAL INSTRUMENTS CORP 11500 N. MOPAC EXPRESSWAY AUSTIN TX 78759 1 0 0 0 Common Stock 2010-11-22 4 S 0 2000 34.2603 D 634330 D Common Stock 2010-11-22 4 S 0 2000 34.2603 D 634331 I by Spouse Common Stock 2010-11-22 4 S 0 2000 34.2603 D 465014 I by Laura Kodosky trust Common Stock 2010-11-22 4 S 0 2000 34.2603 D 465014 I by Karen Kodosky trust Shares were sold under Reporting Person's 10(b)5-1 Plan. The broker erroneously provided information that the number of shares executed on November 22, 2010 was 3,000. The actual number of shares executed was 2,000. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.2407 to $34.2701, inclusive. The reporting person undertakes to provide to National Instruments Corporation, any security holder of National Instruments Corporation or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. The additional 1,000 shares reported on November 24, 2010 have been included in all Form 4s to date. David G. Hugley as attorney-in-fact for Jeffrey L. Kodosky 2011-12-29