The current contract between the nation's fifth-largest rail system and the Service Employees International Union (SEIU), Local 1021 and the Amalgamated Transit Union (ATU), Local 1555, will be extended for 30 days after expiring earlier this week.
"The contract will be extended until August. 4," Morgenstern said. "The parties will continue to negotiate just as hard as they are now."
Morgenstern said he and two top state mediators urged the bargaining parties to agree to an extension of the current labor deal as both groups have said repeatedly that they were far apart in terms of reaching a new deal.
BART General Manager Grace Crunican agreed there is still a wide gap. Key sticking points in the labor dispute include salaries, pensions, health care and safety.
"Unfortunately, the issues that brought us to this point remain unresolved," Crunican said. "Despite lots of hard work, BART and its unions have failed to come to an agreement on contract issues that matter to all of us today and into the future."
Josie Mooney, a chief negotiator for SEIU, Local 1021, said late Thursday that there's still a lot of work left to do and asked the public to keep the parties on task.
"We stand together tonight and we expect to be standing together with a new contract at the end of August 4 and we hope to goodness that you insist that all the parties do the right thing," Mooney said.
BART serves more than 400,000 commuters each weekday. The transit system carries passengers from the farthest reaches of San Francisco's densely populated eastern suburbs to San Francisco International Airport across the bay.
The strike began early Monday after negotiations broke off after the unions said late Saturday they would likely walk away from the bargaining table. Talks resumed Tuesday amid mounting political and public pressure to reach a settlement. The two sides negotiated most of Wednesday as BART issued a statement, saying it was sorry that the actions of the unions had caused such a tremendous disruption.
Meanwhile, the unions remained steadfast that its concerns weren't being addressed.
The strike caused stress and frustration in the region. Commuters lined up early in the morning for the transit agency's charter buses at five locations, waited patiently for ferries heading to San Francisco, and endured heavy rush-hour traffic on the San Francisco-Oakland Bay Bridge, especially on Monday and Tuesday.
BART said that limited bus service would continue Friday.
Prior to the four-day work stoppage, BART's last strike lasted for six days in 1997.
BART has said workers from the two unions average about $71,000 in base salary and $11,000 in overtime annually. The workers also pay a flat $92 monthly fee for health insurance.
The unions — which represent nearly 2,400 train operators, station agents, mechanics, maintenance workers and professional staff — want a 5 percent raise each year over the next three years.
BART said it is offering an 8 percent salary increase over the next four years as well as reducing the amount of employee contributions it originally requested for pension and medical benefits.
Antonette Bryant, the ATU Local 1555 president, said late Thursday that BART is "on notice" and has 30 days to hammer out a deal.
"We're not going to let them hijack us and the riding public and we are deeply sorry this had to happen," Bryant said.