Federal Express Corp. will launch on April 1 an overnight service that delivers documents and small packages in the afternoon instead of midmorning at a slightly reduced rate, the company said.

The new FedEx Standard Overnight service promises next-afternoon delivery for packages up to 5 pounds, arriving by 3 p.m. in most areas or 4 p.m. in more remote locations. The current Priority Overnight delivery program promises deliveries by 10:30 a.m. in most locations."We saw a niche in the market for those people wanting a lower cost service for next-day delivery, but not necessarily next-morning delivery. We already have a priority overnight service," spokesman Armand Schneider said last week.

For letter delivery, the company said its door-to-door list price of from $8.25 to $11.25 would be the lowest in the industry.

"Test marketing of the new product in six cities confirmed that many customers who use our competitors do so when price is the prime factor," said Carole A. Presley, senior vice president for marketing and communications.

The door-to-door list price for packages would range from $12.50 for a 1-pound package to $16.50 for a 5-pound package.