COMING SUNDAY: More details on the Atlanta Symphony Orchestra’s mediated settlement and what it means for the future of the biggest performing arts organization in the Southeast.

After 10 months of discordant contract negotiations between Atlanta Symphony Orchestra management and musicians, including a two-month player lockout, resolution is at hand.

The Federal Mediation and Conciliation Service, which restarted stalled talks a month ago, released a statement late Friday afternoon announcing a tentative accord between the two sides.

“The parties have been faced with complex issues and some very tough choices, which they were dedicated to resolving,” said FMCS acting director Allison Beck. “This tentative agreement will help ensure the continuing viability of one of the premier cultural institutions of the South.”

Concerts are likely to resume Nov. 20-23.

Though the statement did not provide details of the four-year pact, a source close to the negotiations confirmed that the sides compromised on the biggest issue, the size of the orchestra. (The source did not want to be identified because the deal is pending approval.)

Assuming both sides OK the contract, the ASO, which was trimmed from 95 to 88 full-time players in the 2012 collective bargaining agreement, will start the delayed 70th anniversary season with the 77 remaining musicians.

That would be the contracted number for the second year, 2015-16, as well, but management would have the goal of raising the “complement” to 81 full-time players. The administration would contractually commit to 84 full-time positions by the end of 2016-17 and a minimum of 88 in the fourth and final year.

When the second musician lockout in tw0 years began on Sept. 7, the musicians had proposed a complement of 84 in year one, rising to 86, 88 and 89 in subsequent years.

Without committing to specific numbers, management had proposed a unique arrangement before the lockout in which it would negotiate with music director Robert Spano and musician representatives on whether and how individual musician positions would be filled as they became open. In cases where there was not a consensus, the administration would have had the final say.

Pointing out that fixed complements are set in the contract of every major American orchestra, the musicians wanted no part of that.

“There is no trust that (management) has the best intentions of this orchestra, except to try to get a balanced budget, even if it means you have an orchestra with 50 pieces, ” Daniel Laufer, an ASO Players’ Association negotiating committee member and ASO cellist, said at the time.

ASO and Woodruff administrators said they had no choice but to further cut the complement as part of a strategy to halt 12 consecutive years of orchestra deficits, including $2 million in fiscal 2014.

The musicians have repeatedly said since that further reduction in their ranks, requiring a reliance on substitute players, would turn the Grammy-winning orchestra into a minor-league group. And though maestros usually stay neutral in labor disputes, music director Robert Spano vigorously supported them, telling The New York Times, “Would you want the Falcons playing with one quarterback?”

No talks were held for a month after the lockout, but the musicians were hardly silent, issuing a stream of statements accusing Woodruff leaders of mismanagement an even malfeasance. Finally, both sides agreed to bring in the federal mediators, who began work Oct. 7.

Though the mediators don’t have the power to force either party to accept terms, they can nudge compromise little by little. Both sides have highly praised the work of Beck and Virginia-based mediator Richard Giacolone, who conducted the last two rounds of mediation solo.

Pay was the other issue demanding resolution. Before this week’s talks, management had not changed its offer of 4.5 percent raise over the four years. The musicians had moved from proposing a 15 percent raise to one closer to 10 percent.

It’s not known where the final figure stands.

The musicians are believed to have begun voting on terms Friday. If the majority of players approve it over a 24-hour period, the deal would immediately go to the Woodruff’s governing board for final approval, probably as soon as this afternoon.

A spokesman for ASO and Woodruff management declined comment about the pending deal Friday, and leaders of the Players’ Association did not respond to interview requests from the AJC.

In late September, management cancelled the initial eight performances of the orchestra’s 70th anniversary season, leaving concerts scheduled to start up again on Nov. 13 and 15. However, with ASO musicians guesting with a variety of orchestras this weekend, it’s assumed that season-opening concerts will be delayed one more week, to allow for a reasonable number of rehearsals.