Senate Majority Leader Robert C. Byrd (D-W. Va.) proposed yesterday a series of rules changes designed to eliminate delaying tactics used by a minority of members.

The changes would not affect the right of senators to conduct a filibuster nor would they alter current rules on shutting off a filibuster. But if adopted they could have a substantial effect on the way the Senate conducts its business.

Byrd has been increasingly frustrated by members who have used existing Senate procedures to prolong debate on an issue, especially after the Senate has voted to stop a filibuster. The tactics have been used by comservatives and liberals alike, and the threat of such delays has kept some legislation from reaching the floor.

The most important change in Byrd's package, which will be offered when the news Senate convenes Monday, could limit debate to 12 hours once a filibuster been stopped.

Current rules require 60 votes to end a filibuster. Once that clothre petition has been approved, each senator is then allowed one additional hour for debate.

In practice, however, parliamentary devices are available to extend that 100-hour limit indefinitely.

Byrd's proposal would set a strict 100-hour limit on debate after cloture has been invoked. The 100 hours would include time spent on delaying votes, quorum calls and other diversions.

The 100-hour limit could be increased or reduced to as few as 12 hours by a vote of 60 senators. A motion to reduce the time could not be offered until after at least 10 hours of debate.

Byrd also proposed a rules change to end the threat of a filibuster on procedural motions to take up controversial legislation. Filibusters can be mounted on these procedural motions, giving opponents in effect two opportunities to filibuster the same bill. Byrd would set a strict 30-minute time limit for debate on such motions.

Other changes would:

Allow a three-fifths vote to require that only amendments germane to a bill be in order;

Reduce from three days to two the time required before a committee report can be considered by the Senate, and allow weekends and holidays to be counted if the Senate is in session;

Allow a motion to suspend reading of the Senate journal to be considered without debate, instead of requiring unanimous consent;

Permit a majority to waive reading of an amendment or a conference committee report if it is available in printed form.

Republicans and some conservative Democrats can be counted on to oppose any rules change, but the most formidable opponent of any alterations in the rules in recent years is no longer on the scene. The was Sen. James B. Allen (D-Ala.), a master of parliamentary technique, who died last year.

Another new factor this year -- which will bring the first significant rules fight since 1975 -- is the presence of Walter F. Mondale in the vice president's chair, presiding over the Senate. Depending on what approach to rules changes Byrd takes, Mondale's rulings from the chair could be crucial.

As a senator Mondale was a leader of the 1975 attempt to reform the rules, which resulted in a liberalizing change in the cloture procedure. At that time he argued that a new Senate has the right to revise rules by a simple majority vote, since the rules of a previous Senate cannot bind a new one. (Existing Senate rules say it requires a two-thirds vote to change a rule.)

Vice President Nelson Rockefeller agreed with Mondale in 1975, and so ruled. Now Mondale can take the same position.