United Parcel Service has told its white-collar employees that it will stop providing health care coverage to their spouses who can obtain coverage through their own employers, joining an increasing number of companies that are restricting or eliminating spousal health benefits.

U.P.S., the world’s largest package delivery company, said its decision was prompted in part by “costs associated with” the federal health care law that is commonly called Obamacare. Several health care experts, however, said they believed the company was motivated by a desire to hold down health care costs, rather than because of cost increases under the law.

In a memo addressed to employees, U.P.S. said, “Limiting plan eligibility is one way to manage ongoing health care costs, now and into the future, so that we can continue to provide affordable coverage for our employees.”

The memo also estimated that about 33,000 spouses were covered under its insurance plan for white-collar employees and that “about 15,000 of these would have health care coverage available through their own employers.”