Senators earned more than three-quarters of a million dollars in outside income in 1976 for speeches before lobbying groups, unions, charities and educational organizations, Senate records show.

Althought a handful of reports are still out, the records show that the 91 current and former senators who have filed so far earned an aggregate of $770,700 in 1976 for addressing groups like the American Meat Institute, the Insurance Information Institute, Yale University students, the Christian Life Commission, the hotel and restaurant workers and the like.

That brings to nearly $5 million the total in outside speaking fees earned by senators over the past six years.

Senators have frequently been criticized for such speeches, on grounds the fees may be little more than a concealed "good will" payment from an organization that wants something from congress and would like to get on a senators good line.

They have also been criticizd for running off to earn speaking fees at times they should be on the floor voting.

For that reason, Congress a few year ago placed a limit of $15,000 per year on speaking fees, then raised it to its current figure of $25,000. Earlier this year a new Senate code of ethics lowered the figure to $8,625 but that won't take effect until Jan. 1, 1979.

The outside speaking fees are in addition to a senator's regular Senate salary, which was $44,600 in 1976 but which since has been raised to $57,500.

All told, 32 senators in 1976 earned $10,000 or more from the outside fees, with Herman Talmadge (D-GA.) the leader at $25,000. Eighteen senators, including both Virginia senators and J. Glenn Beall (R-MD.), who was defeated for re-election, reported earning nothing in outside fees for speeches or articles.

Records complied by The Washington Post and Congressional Quarterly show these total for senatorial honoraria for the past six years:

1976 - $770,700 1973 - $1,087,000

1975 - $638,000 1972 - $618,000

1974 - $940,000 1971 - $787,000

Here is a list of the 32 senators whose earnings were $10,000 or more last year from speeches and articles:

Some of the men on this list have left the Senate since last year, some through retirement, others through defeat, Mondale to become Vice President.

All nine of those have who failed to report so far are senators who have left office.

Earlier this year, when the Senate imposed the $8,625 limit on honoraria, starting in 1979, Packwood (the second highest earner in1976) and Muskie (17th) strenuously opposed the lower limit. Muskie said bluntly he would find it hard to live just on his Senate salary and only $8,625 extra in honoraria. However, the limit was imposed anyhow.