After two days of marathon negotiations — and mounting frustration throughout the league — the NFL and the officials’ union announced at midnight Thursday that a tentative eight-year agreement had been reached to end a lockout that began in June.

The deal came on the heels of the Seattle Seahawks’ chaotic last-second win over the Green Bay Packers on Monday night in which the replacement officials struggled. Commissioner Roger Goodell, who was at the bargaining table Tuesday and Wednesday, said the regular officials would officiate the Browns-Ravens game at Baltimore on Thursday night.

“We are glad to be getting back on the field for this week’s games,” NFL Referees Association president Scott Green said.

And plenty of players echoed that sentiment.

“Welcome back REFS,” Buffalo Bills running back C.J. Spiller tweeted shortly after the news broke.

The tentative deal must be ratified by 51 percent of the union’s 121 members. They plan to vote Friday and Saturday in Dallas.

For the Packers, Redskins, Lions and other teams who voiced their displeasure with calls that might have swayed games, the agreement doesn’t change their records. But after having replacements for the first three weeks, triggering a wave of outrage that threatened to disrupt the rest of the season, Titans quarterback Matt Hasselbeck probably spoke for his peers by simply echoing Spiller: “Welcome back.”

The agreement hinged on working out pension and retirement benefits for the officials, who are part-time employees of the league. The tentative pact calls for their salaries to increase from an average of $149,000 a year in 2011 to $173,000 in 2013, rising to $205,000 by 2019.

Beginning with the 2013 season, the NFL will have the option to hire a number of officials on a full-time basis to work year round, including on the field. The NFL also will be able to retain additional officials for training and development, and can assign those officials to work games. The number of additional officials will be determined by the league.

“As you know, this has to be ratified and we know very little about it, but we’re excited to be back. And ready,” referee Ed Hochuli told The Associated Press in a telephone interview. “And I think that’s the most important message — that we’re ready.”

After Seattle’s 14-12 victory against the Packers, the replacement referees’ ability to call fast-moving NFL games drew mounting criticism, with ESPN analyst Jon Gruden calling their work “tragic and comical.”

The Seahawks beat Green Bay on a desperation pass into the end zone on the final play. Packers safety M.D. Jennings had both hands on the ball in the end zone, and when he fell to the ground in a scrum, both Jennings and Seahawks receiver Golden Tate had their arms on the ball.

The closest official to the play, at the back of the end zone, signaled for the clock to stop, while another official at the sideline ran in and then signaled touchdown.

The NFL said in a statement Tuesday that the touchdown pass should not have been overturned — but acknowledged Tate should have been called for offensive pass interference before the catch. The league also said there was no indisputable evidence to reverse the call made on the field.

That drew even louder howls of disbelief. Some coaches, including Miami’s Joe Philbin and Cincinnati’s Marvin Lewis, tried to restore some calm by instructing players not to speak publicly on the issue.

Fines against two coaches for incidents involving the replacements were handed out Wednesday.

Patriots coach Bill Belichick was docked $50,000 for trying to grab an official’s arm Sunday to ask for an explanation of a call after his team lost at Baltimore. And Washington offensive coordinator Kyle Shanahan was fined $25,000 for what the league called “abuse of officials” in the Redskins’ loss to Cincinnati on Sunday. Two other coaches, Denver’s John Fox and assistant Jack Del Rio, were fined Monday for incidents involving the replacements the previous week.

“I accept the discipline and I apologize for the incident,” Belichick said.

Players were in no mood for apologies from anyone.

“I’ll probably get in trouble for this, but you have to have competent people,” Carolina receiver Steve Smith said. “And if you’re incompetent, get them out of there.”

And now they are out.

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AP Sports Writers Tim Reynolds in Miami, Steve Reed in Charlotte, N.C., and R.B. Fallstrom in St. Louis contributed to this story.