WASHINGTON (AP) — The number of people seeking U.S. unemployment benefits rose 68,000 last week to a seasonally adjusted 368,000, the largest increase in more than a year. The surge could be a troubling sign if it lasts. But it likely reflects the difficulty adjusting for delays after the Thanksgiving holiday. The Labor Department says the less volatile four-week average rose 6,000 to 328,750. That is close to pre-recession levels and generally a positive sign for job gains. Applications for unemployment aid are a proxy for layoffs. A steady decline over the past year suggests that fewer Americans have lost their jobs. Economists will track the next few weeks closely to see if that trend is reversing, or if the surge is a temporary blip caused by seasonal adjustments.