Negotiations in the baseball strike broke off again last night, and federal mediator Kenneth E. Moffett said the situation is "worse than before. It's bad, bad, bad. Why? Because the parties are really locked into their positions."

However, negotiators for the owners and players differed considerably in their assessments of the situation. Marvin Miller, executive director of the Major League Baseball Players Association, said the players became convinced last night the owners "do not want a settlement."

Ray Grebey, the owners' chief negotiator, said the two sides "were closer than ever."

The negotiators met at the Federal Mediation and Conciliation Service jointly and separately on the 42nd day of the strike, a day that began with the highest hopes yet for a settlement. Now the date of the next meeting, much less the next baseball game, is in doubt.

Moffett said he would be in touch with the parties, but that he did not expect to call a meeting before Wednesday. The board of directors of the owners' Player Relations Committee met after last night's negotiations. The executive board of the players association will meet early next week. The sites of next week's talks and association meeting have not been determined.

Although there were thanks all around for the efforts of Secretary of Labor Raymond J. Donovan, who had invited the two sides to continue the negotiations this week in Washington, his participation clearly was not enough. Moffett said it is "a good possibility" that Donovan will not continue to be directly involved in future negotiations.

Grebey said Donovan "helped us to narrow our differences significantly."

Miller said, "I would not quarrel with the assessment that we succeeded in narrowing some differences. We succeeded not at all in the heart of the matter."

The parties spent the last two days, Miller said, attempting to negotiate a settlement on the basis of a pooled player compensation proposal made by the players on Tuesday. In that proposal, they adjusted downward the level of compensation for a premium free agent to the 24th man on the roster.

However, each time the players tried to address the owners' problems with the proposal, Miller said, "Something new popped up that wasn't good until we became convinced tonight they do not want a settlement."

The owners, Grebey said, made two proposals over the couse of the last 24 to 48 hours that will be presented to the players in writing. He declined to describe them in detail, except to say that one was a variation of the pooled concept and another a variation on the direct compensation.

"The players association told that because of areas of difficulties they feel it is necessary to call a meeting of the executive board early next week. . . Hopefully, with that effort, we will produce a settlement."

The implication was that he thought the executive committee would be voting on those proposals, but when asked if that was his expectation, Grebey said, "I do not feel it is appropriate for me to comment on their internal affairs."

Miller said, "If they think we are taking the proposal to the board for a vote, they are absolutely wrong." As the owners' proposal stands now, he said, the bargaining committee will not recommend to the board that it be accepted.

A four-day news blackout requested by Donovan was ended by agreement of the principals.

According to Don Fehr, the players' general counsel, the owners propose that each team place its 29th man on its roster in the pool and that the team could lose that player only once every three years. However, if a team signed a quality free agent, then it also had to put the 25th man on its roster in the pool. If the team signed two quality free agents, Fehr said, the team would have to put its 25th, 26th and 29th man in the pool and potentially could lose each of them.

The optimism that surrounded the talks as recently as early yesterday was due, in large measures, to a proposal for pooled compensation made by the owners. But, Miller said, while the owners "pretended they were negotiating on a pool concept, they have come up with a proposal the heart of which is direct compensation" that still punishes a team signing a free agent.

That philosophical chasm dwarfs the progress made in several other areas. The two sides, Miller said, agreed that:

Ranking free agents, those for whom professional compensation would be required, would be those players in the top 20 percent of performance statistics.

Compensation for those ranking free agents would be a pooled player, as well as an amateur draft pick taken from a special round in the draft.

Free agents falling between 20 to 30 percent in performance statistics would be Type B free agents, requiring nonprofessional compensation.