NEW YORK » FedEx expects to move nearly 16 million packages on its busiest day this year, Dec. 13. The prediction is FedEx’s highest ever for a single day and 11 percent higher than last year.

More than half the increase is from its partnership with the U.S. Postal Service, FedEx Corp. said today.

Those shipments are mostly for consumers who are ordering from online retailers during the busy holiday shopping season.

Last year the Memphis, Tenn., company shipped 14.2 million packages on its busiest day. FedEx’s larger rival, Atlanta-based UPS, hasn’t yet made any predictions. FedEx ships about 7.5 million packages on an average day.

During the week of Dec. 13, the company expects to move more than 63.1 million packages, compared with last year’s busiest week of 57.5 million. FedEx says driving those numbers will be books from large Internet retailers, clothing, consumer electronics and luxury goods.

Peak projections from UPS and FedEx are closely watched by economists because they can signal how the broader economy is doing. Consumer spending accounts for about 70 percent of U.S. economic activity and is critical to a strong rebound.

Many of those consumer goods are shipped via FedEx and UPS.