Cramer: Activism in UAL ‘ridiculous’

The activists going after United Continental Holdings should go after someone else, CNBC's Jim Cramer said Tuesday.

Cramer noted that United has outperformed the S&P 500 index by 90 percent to 28 percent over the past three years, and by 18 percent to 6 percent over the last two.

"Why can't these guys go after someone who didn't do a good job?" Cramer asked on "Squawk on the Street." "This is ridiculous; this is a good stock and getting better."

Earlier Tuesday, activist investment firms PAR Capital Management and Altimeter Capital said in a letter they will nominate six members to the board of directors, including former Continental Airlines CEO Gordon Bethune.

One of the reasons cited by the firms is United's stock performance, which they characterize as "poor." "United has been the worst performing U.S. airline stock over the last five years," they said.

PAR and Altimeter did not immediately respond to a CNBC request for comment.

Over the past five years, United shares have gained nearly 128 percent, while the S&P has risen 52 percent. Shares of rival airline Delta have risen over 300 percent in the past five years, while Southwest Airlines has seen its stock rise 224 percent.

Shares of United Continental were down over 2 percent.

Disclosure: Cramer's trust did not own shares of United Continental when this article was published.