The United Auto Workers on Monday evening issued an "official call" to local union leaders to come to the Renaissance Center for a national council meeting on Thursday.

General Motors Co. and the union still are at the bargaining table, and there is not yet a tentative agreement, two people familiar with the talks told The Detroit News. A spokesman for the automaker confirmed talks are continuing.

The union must call the 200 local leaders representing GM employees to Detroit to vote on a proposed tentative agreement once one is reached. They also will decide when to end the national strike, now in its fifth week.

The meeting will convene at 10:30 a.m. in the ambassador ballroom of the Marriott hotel at the Renaissance Center, according to the call letter. The UAW would not comment further on why the meeting is being held.

The released notice comes after UAW leaders said this weekend they were pulling out their "arsenal" to increase pressure on GM to make a deal, but investors say they feel no rush so long as the automaker's labor costs don't rise, according to an analyst note Monday.

"Investors we have engaged with are comfortable with extended strike duration and potential upfront multibillion-dollar financial impact as long as GM preserves long-term cost and strategic flexibility," wrote Adam Jonas, a Morgan Stanley & Co. LLC analyst.

The national strike against GM entered its 29th day Monday, as officials met at 8 a.m. at the bargaining table after pausing at 10 p.m. Sunday. The parties made progress over the weekend, but unsettled issues remain — one being in-progression employees, according to a source with knowledge of the situation.

It takes eight years for new permanent hires to get to the top of the pay scale. The union wants to reduce the time it takes to get to the top. GM, meanwhile, is looking to limit increases to total labor costs, which already are $13 per hour per employee higher than foreign automakers manufacturing in the United States, according to the Center for Automotive Research in Ann Arbor.

The automaker and the UAW took shots at each other in the press last week as bargainers failed to reach an agreement. The UAW approved a 10% increase in pay for the 49,000 GM-UAW employees who walked off the job. Striking members began picking up the now-$275-per-week check Monday.

Local union leaders in Fort Wayne, Indiana, and Bowling Green, Kentucky, also last weekend pulled skilled maintenance employees who work on boilers and heating and cooling units in their respective GM plants. The so-called powerhouse employees perform "critical and essential functions," the leaders said, and typically continue to work in the plants even when there is a strike. GM said the move does not impact safety or security at its facilities.

A four-week strike "is a little extreme," said Rich LeTourneau, GM chair of UAW Local 2209 in Fort Wayne. "We can handle it, but hey, now it's time to pull out all your arsenal."

GM's shares are down nearly 9% since before the strike began. Jonas on Monday forecasted that a lack of inventory at dealerships could start to hurt retail volumes about now, but he predicted GM largely could restock dealerships to adequate levels through the first half of 2020. At this time, the automaker's 2020 results should not be affected, Jonas said.

"Some investors view today's pain as tomorrow's tight inventory and strong pricing," he wrote. "While we're optimistic ... we question whether that may be a bit of a stretch."

In a video on Sunday, UAW Vice President Terry Dittes thanked members for "holding the line." Dittes called the move to increase strike pay "a big step" by the union's international executive board, done to show appreciation for the striking members who "bring the power to us at the negotiations table."

"When we decided to strike, that was our last resort. We were forced into that situation by General Motors," Dittes said Sunday. "We will continue this fight until we know that we can satisfy your needs of your family, all the members we represent and we can move forward and set an agenda for all workers around this country."

The automaker and UAW have been exchanging and reviewing contract proposals since July. Discussions intensified when the two sides failed to reach a tentative agreement before the Sept. 14 contract deadline, and the union ordered a strike.

Since then, a number of proposals have been shot down. Most recently, the UAW on Friday submitted another counterproposal, which GM reviewed, and talks continued.

The union's proposal is a counter to the offer GM made Oct. 7. The automaker said it included higher wages, secured the union's health care benefits and gave temporary employees a path to permanent employment.

The union's counterproposal included "all of your outstanding proposals that are at the main table and unsettled," Dittes wrote in a letter to local union leaders Friday. He said the parties would have a tentative agreement if GM accepted it.

The UAW-GM strike isn't the only strike the union is overseeing as it works through the negotiation process with two other companies: Aramark Corp. and Mack Trucks Inc.

The UAW's 850 members employed by Aramark, which provides maintenance at five GM facilities — Hamtramck, Warren, Flint, Grand Blanc and Parma, Ohio — have been on strike since Sept. 15.

More than 3,600 UAW members employed by Mack Trucks walked off the job Sunday over issues including wage increases, job security, wage progression, and health and safety.

ithibodeau@detroitnews.com

Twitter: @Ian_Thibodeau