MERRIMACK, N.H. — Governor Richardson of New Mexico ended his campaign for the presidency yesterday after twin fourth-place finishes that showed his impressive credentials could not compete with his rivals’ star power.

Mr. Richardson planned to announce the decision today, according to two people close to the governor with knowledge of the decision. They spoke on a condition of anonymity in advance of the governor’s announcement.

The Richardson campaign would not comment on the governor’s decision, reached after a meeting with his top advisers yesterday in New Mexico.

Mr. Richardson had one of the most wide-ranging resumes of any candidate ever to run for the presidency, bringing experience from his time in Congress, President Clinton’s Cabinet, in the New Mexico statehouse as well as his unique role as a freelance diplomat. As a Hispanic, he added to the unprecedented diversity in the Democratic field that also included a black and a woman.

But Senators Clinton and Obama dominated the spotlight, and Mr. Richardson was never able to become a top-tier contender. He accused his rivals of failing to commit to bring troops home from Iraq soon enough.

He portrayed his campaign as a job application for president and ran clever ads that showed a bored interviewer unimpressed with his dazzling résumé. But he was not able to build the momentum and came in a distant fourth place in Iowa and New Hampshire. Mr. Richardson didn’t get quite 5% in the New Hampshire primary yesterday and came in with just 2% in the Iowa caucus last week.