Every job candidate knows — on time, with a smile and a firm handshake. But it's less clear how to end a job interview in a way that makes you stand out from the competition. According to best-selling management author and CNBC contributor Suzy Welch, the last few minutes of a job interview can make or break your chances of getting the job. And there's something you can say to ensure that you're memorable — in a good way. After you've made your case and the hiring manager concludes the interview, don't just say "thank you" and leave. Before you exit, be sure to say: "I really want this job."

CNBC Contributor Suzy Welch.

While you may worry that being so honest sounds desperate, Welch says the rewards are worth the risk. The statement demonstrates three character traits hiring managers are looking for:

1. Sincerity

"Coming right out and saying 'I really want this job' shows a refreshing level of sincerity," she says. "It always strikes people the right way." There's a simple reason for this. Going off-script shows that you're authentic, a quality Welch notes is "in very short supply in the world." In fact, that for qualified and experienced candidates, demonstrating candor in interviews can pay off.

2. Courage

Firmly expressing that you want a job also requires drawing on your personal strength. "The person hearing it knows it's difficult to say," Welch says. "They know it takes moxie, and they'll remember that." Managers appreciate employees who show courage at work, whether it's reliably taking initiative or speaking up when something is wrong.

3. Humility