PHILADELPHIA, SEPT. 24 (THURSDAY) -- Negotiators for the 28 National Football League owners and the league's striking players resumed negotiations Wednesday for the first time since Sept. 15, meeting nearly nine hours -- until 2:20 a.m. this morning -- on the issue of whether to grant the players' demand for less restrictive free agency. The talks are expected to resume at 10 a.m. today.

After the talks recessed, Brian Holloway, an NFLPA vice president, said that free agency is no longer the major issue.

"The meat of the negotiations tonight is getting ready to unfold," Management Council spokesman John Jones said at a midnight news briefing at the Four Seasons Hotel. "The preliminary work is out of the way so all the focus is on {free agency}. The negotiation process will determine how long they're at the table."

Union president Marvin Powell of the Tampa Bay Buccaneers said during a 2 1/2-hour dinner break that the union expected to negotiate "around the clock."

Earlier, Jones said the owners have not changed their resolve to keep the current system of free agency intact, while offering to liberalize it. "This is about free agency and where the union is at at this time," Jones said.

"We are willing to negotiate and move, but only if there is reciprocity," Powell said.

The Management Council's executive director, Jack Donlan, said two days should be sufficient to determine "whether the union is prepared to . . . take a new direction in free agency." It was to be decided Thursday whether officially to cancel this Sunday's games.

Most of the league's 1,585 players walked out Tuesday as the union called the second strike in the last six seasons. Although the union says seven issues separate the two sides, the owners have said the players' desire for free agency is the only thing preventing the signing of a new three-year contract.

On the second day of the strike, replacement players began crossing union picket lines as the owners went ahead with their plans to resume play on Oct. 4. In Kansas City, Mo., two striking players waved rifles and yelled, "Where's the scabs," and at Redskin Park in Herndon, defensive tackle Darryl Grant pounded and broke the window on a bus carrying replacement players.

Later, the team obtained a temporary restraining order forbidding players from picketing on Redskins property or "committing acts of force or violence."

"I don't want to convey any sense of false hope or expectations," Jones said of the resumption in talks. "There is dialogue, there is discussion, but there is no sense that a settlement is at hand."

"Right now it's going slowly but hopefully we'll all be back to work very soon," Powell said. "And if not, we'll just do what we have to do."

He said no issues had been resolved and that the negotiators were just starting detailed talks about free agency. Nevertheless, he appeared to be cautiously optimistic.

"I'm pleased there's finally a dialogue," Powell said. "I'm pleased that at least we perceive the appearance of cooperation. Let's leave it at that."

The owners have said they would allow only slight modifications in the current free agency system, which gives a player's team the right of first refusal and requires compensation with a high-round draft pick for the club if it loses a player to another team. The union has proposed that players who have completed four years in the league be free to move.

Under the current system, only one player has switched teams in 10 years.

"The next two days are critical," said Donlan. "If there's no movement after two days, we're looking to a long one."

Jones recalled the 57-day strike by the NFLPA in 1982 that caused seven games to be canceled.

"Their membership was impressed by the fact there were meetings going on and they remained on strike," he said. "Donlan thinks it would be both a disservice to the players who are on strike and to the public to hold lengthy meetings that might not necessarily indicate that there would be something happening that might bring about a settlement. . . . It would send a mixed signal."

Sources close to the owners said this is part of Donlan's strategy for putting pressure on the union to break ranks, cross picket lines and join replacement players.

The owners think, the source said, that the prolonged negotiations during the 1982 strike helped the union.

Even though this weekend's games have not been postponed officially, Commissioner Pete Rozelle said Tuesday it would be "very, very unlikely" games would be played this week unless the strike were settled by tonight.

Gene Upshaw, the executive director of the NFL Players Association, said there was no time frame as far as he was concerned. "I'm hoping we can get it done," he said. "That's why we're here. Our agenda is to reach an agreement no matter what it takes."

The resumption of negotiations came about after Upshaw met Tuesday with Rozelle, who brought Upshaw and Donlan together for 90 minutes. The talks included an expanded group of bargainers, something for which Upshaw had been pressing.

President Dan Rooney of the Pittsburgh Steelers, considered a moderate among owners, and president Tex Schramm of the Dallas Cowboys, considered a hard liner, joined the talks at Upshaw's request.

Holloway, one of at least nine players here instead of the picket lines, said upon arriving he was hopeful that a quick settlement was achievable. "The reason why," he said, "is that the executive committee left instructions that, not until it looked like things were going to move or are moving, to call us in."

At the negotiating session as observers were Reggie White, Mike Quick and John Spagnola of the Philadelphia Eagles. Player participants included Powell, Mike Kenn and Mick Luckhurst of the Atlanta Falcons and Mike Davis and James Lofton of the Los Angeles Raiders. Dan Marino of the Miami Dolphins, George Martin of the New York Giants and former Seattle Seahawk Michael Jackson were expected to join the talks later.

There were no new proposals on the table when yesterday's sessions began. Using figures of the opposite sides, there is a $288 million difference, not to mention the free agency issue, between the owners' offer of Sept. 7 and the players' Sept. 15 counterproposal.

The players say the Sept. 7 owners' offer would take back $88.3 million in benefits they had last season. The owners say the players' counteroffer adds $200 million to their 1986 costs.

Meanwhile, at least two major TV sponsors will consider not advertising if the owners play games with replacement players. Chrysler Corp. and Ford Motor Co. said last night they were unsure about what they would do with their advertising budgets if the NFL fields strike-breakers.

"We bought time for the Lions and the Bears {Sunday}, not the cookie monsters," B.F. Mullins of Chrysler said. "We deal with the networks on a weekly basis to decide what to do. We can say, 'Give us our money back . . . ' " Washington Post staff writer Michael Wilbon in Washington contributed to this report.