The Labor Department yesterday proposed technical revisions in pension regulations that would allow managers greater flexibility in investing the country's $560 billion in pension assets.

Banks, insurance companies and investment advisers will be granted a class exemption to engage in sales, loans, leases, extensions of credit and exchanges of property with parties in interest without violating the law. At present, the Labor Department grants exemptions on a case-by-case basis.

Last year, approximately 1,000 applications for exemptions were filed. About half of all applications are granted. The process takes four to five months. It is estimated the revision in the 1975 Employe Retirement Income Security Act will save millions of dollars in staff time spent checking to see if the company or union has a financial interest in a project in which the pension fund invests and, if so, filing for an exemption. The savings may be passed on to the funds.

An additional cost -- one that cannot be estimated -- is that of lost investment opportunities because of the long delays caused by compliance with regulations.

The change, which has been sought for years, particularly by the insurance industry, reflects the Reagan administration's philosophy of cutting red tape and giving business more latitude. Labor Secretary Raymond J. Donovan called it a "policy shift from a paternalistic approach to prudent deregulation."

He cited the following example: Were AT&T to buy a shopping center with its pension fund and also install a telephone distribution center in the same location, it would have to request an exemption under the old regulation. In the same sense, a union seeking to invest in the shopping center could not do so if any union members work at the center.

The change will grant a class exemption for 90 percent of banks (those with $1 million in equity), 75 percent of insurance companies (with $1 million net worth) and 50 percent of investment advisers (with $50 million under management). It is expected that some smaller or in-house advisers may complain about the rule.

The ERISA was enacted in 1975 to protect workers' pensions and to eliminate abuses involving the use of corporate funds. The revision proposed yesterday would not affect prohibitions against self-dealing -- such as a manager using the funds to make personal gains.