Package delivery company FedEx Corp. said Tuesday that it is making changes to its pension plan and increasing its matching contributions to 401(k) plans. The company said most eligible employees who participate in a pension plan will begin accruing future benefits under a cash balance formula called portable pension account starting on June 1, 2008. Benefits accrued under a traditional pension benefit formula will be capped on May 31, 2008 and paid monthly at retirement. FedEx said the changes are a result of shifting demographic trends, the federal Pension Protection Act and recently adopted and proposed changes in accounting rules. The company is also raising its matching contributions for most workers and providing additional investment options under its 401(k) plans. How long before UPS follows?