Health insurance costs for federal workers and retirees will increase an average of 40 percent next year, raising premiums of some key plans by amounts ranging from $ 60 to more than $ 360 a year, according to information released yesterday by the Office of Personnel Management.

The OPM announcement, made in preparation for the Monday opening of the court-ordered "open season" that allows employes to shop around for health insurance, ended months of speculation on 1982 costs and benefits negotiated under the Federal Employees Health Benefit Program.

As rumored for weeks, the price tag on many of the 126 plans in the program has jumped considerably. The popular high-option family plan offered by Blue Cross/Blue Shield, for instance, now will cost each employe about $ 1,160 next year compared to the approximately $ 800 the plan currently costs. The roughly $ 360 premium increase would claim more than one-fourth of the 4.8 percent salary raise the average white collar federal worker in Washington received this year.

There are widely varying changes in costs among the 126 plans. Premiums for some of the less-widely used plans will jump far more than for Blue Cross/Blue Shield, while others will remain about the same or decline slightly, raising the possibility of large-scale movement out of some plans and into others.

The government's health insurance program covers about 10 million federal employes, retirees and their dependents, including nearly 1 million Washington area residents.

The federal government generally pays 60 percent of the total premium costs, based on a formula that takes the average premium cost of the six largest plans in the program. It pays 75 percent of premium costs for postal workers because of contracts won by postal unions.

Based on those figures, OPM estimates the premium increases will cost the government $ 500 million next year, bringing the total government contribution to $ 2.5 billion.

Details on the various health insurance plans will be contained in individual brochures expected to be ready for general distribution by Dec. 18. In the meantime, OPM has prepared a 62-page news release, which is being sent to all federal departments and agencies and which will contain copies of "change page" material describing benefit and cost alterations in each of the plans.

The open season, ordered by a federal court after several employe unions successfully sued to block OPM efforts to cut benefits and costs, will last through Dec. 31.

The Blue Cross/Blue Shield premium increases were considered the most dramatic since that carrier insures about 60 percent of all government workers here. Some of the other plans used by area employes also will experience premium increases, which usually are deducted from employe paychecks every two weeks.

Other major insurance plans covering Washington area workers include Aetna Life Insurance Co., where biweekly premium costs for employes will increase by $ 1.81 for high option family coverage and $ 4.44 for low option family coverage; the American Federation of Government Employes, a $ 7.94 biweekly increase for high option family coverage; the Alliance Health Benefit Plan, a $ 16.15 biweekly increase for high option family coverage; and the American Postal Workers Union Plan, which now will cost $ 7.07 more in biweekly payroll deductions for high option family coverage.

One plan used by the National Association of Postmasters of the United States actually will decline by 60 cents in biweekly deductions. Nearly all the others used by area workers will increase. The Foreign Service Benefit Plan will go up by $ 6.71 in biweekly deductions for high option family coverage. The Mail Handlers Benefit Plan will increase by $ 3.26 for high option coverage, and the National Treasury Employes Union plan now will cost $ 9.12 more in biweekly deductions for high option family coverage.

NTEU went to court yesterday in an unsuccessful attempt to have OPM director Donald J. Devine held in contempt. The union claims the agency has failed to provide U.S. workers with enough information to decide whether to continue current health coverage or switch to other plans. Noting the increases in Blue Cross/Blue Shield premiums, an NTEU spokesman said employes should have better access to information about all the various plans and not just a "change page" about how coverage will be altered next year.