U.S. employers posted the highest number of job openings in almost four years in March, signaling that hiring could strengthen in the next few months after slowing in spring, the government said Tuesday. The Labor Department reported that employers posted 3.74 million job openings in March, which was up from a revised 3.57 million in February. March's figure was the highest since July 2008, just prior to the financial crisis. The increase suggests that hiring gains in March and April could be temporary, as it usually takes one to three months for employers to fill job openings. Still, roughly 12.7 million people were unemployed in March, with an average of 3.4 people competing for each open job. It was better than the roughly 7 to 1 ratio when the recession ended. A healthy job market typically has a ratio of 2 to 1. The report, the Job Openings and Labor Turnover survey (JOLTS), showed that more people quit their jobs in March. Economists say that when people quit their jobs, they do so in order to move to new jobs. When quits rise, it usually suggests that workers are finding more opportunities in the job market. Almost 4.36 million people were hired in March, which was slightly fewer than in February. The JOLTS report measures gross job gains, while monthly jobs reports are net figures calculated after subtracting layoffs and quits.