SEATTLE – Three Seattle sports franchises and the Seattle Arena investment group have struck a deal on scheduling.

The Seattle City Council will announce Thursday it has brokered a deal between the Seattle Mariners, Seahawks, Sounders FC, and Chris Hansen’s Seattle Arena investment group on an agreement to manage time and traffic in Seattle’s SODO neighborhood. First and Goal, the Washington State Public Stadium Authority, and the Seattle Public Facilities District also had a hand in the negotiations.

The Mariners, in particular, had made the scheduling agreement a key argument in their opposition to the planned arena development, which would be built just south of Safeco Field.

The agreement will now be a key amendment to the legislation to vacate a one-block stretch of Occidental Avenue, allowing Hansen’s group to build his planned NBA/NHL Arena. The council is slated to vote on the legislation Monday -- the last approval needed before the City of Seattle grants a Master Use Permit for the project.

Two sources with knowledge of the agreement say it is “very comprehensive” and “detailed” and also covers game time easements and access. It also prohibits late afternoon events that would conflict with the Port of Seattle and Northwest SeaPort Alliance operations. The agreement also prevents events at Hansen's arena between the hours of 4 p.m. and 7 p.m. It also calls for a three-hour separation of events between the three potential venues, with some protocols for exceptions, such as for playoff games.

The negotiations have been ongoing for about a week and a half. Those same sources involved with the negotiations have described the Mariners representatives as “very good” and “fantastic” in hammering out the deal.

On Wednesday, the Mariners announced a change in ownership structure and will now be led by former Sonics minority owner John Stanton.

Seattle City Councilmembers Tim Burgess and Mike O’Brien were personally involved in the negotiations at times. Burgess indicated at a council meeting on April 19 that there had been significant progress made by all the parties. O’Brien echoed the sentiment this past Monday when he told his council colleagues there had been more movement from the team and that he would personally be involved.

The question now is whether the agreement is enough for a council majority to approve the street vacation. There are other amendments, like one that would force Hansen to pay for the street vacation and direct the money to the SODO transportation fund. Another will require Hansen to put money into a Lander Street overpass that has been on the Port of Seattle's wish list for years.

Councilmember Sally Bagshaw, who voted to approve the original Memorandum of Understanding on the arena back in 2012, has voiced her disapproval with the street vacation plan and has indicated she will vote no. Councilmember Lisa Herbold is another expected no vote.

Councilmembers Burgess, O’Brien, Bruce Harrell, and Rob Johnson all voted yes on the measure in committee. It needs another vote to pass the full nine-member council.

Councilmembers Debora Juarez, Lorena Gonzalez and Kshama Sawant have not publicly indicated which way they intend to vote.

Follow Chris Daniels on Twitter: @ChrisDaniels5