Updated from 1:32 a.m. EDT


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and the International Association of Machinists have reached a tentative agreement to end a 53-day-old strike.

On Wall Street, a deal to put America's largest exporter back to work came as welcome news. Boeing shares traded Tuesday at $48.91, up 15.5%. Shares had fallen as low as $39.99 this month, their lowest level since March 2004.

The settlement followed five days of talks in Washington, and 27,000 union members are expected to vote this week. The deal has been unanimously endorsed by union leadership.

Key aspects of the preliminary settlement include agreements the union had sought on job protection, no increase in employee health-care costs and a four-year contract, rather than the more typical three. For the first three years, workers get the 11% pay raise that Boeing had offered, with a 4% raise in the fourth year. The IAM had proposed 13% for the first three years.

The contract would also save about 2,200 facilities and maintenance positions and extend job protection for another 2,900 workers. It also "expanded the scope of our subcontracting review" and "secured the ability to compete for work that moves from one Boeing facility to another Boeing facility," according to a union press release. The chance to go after work that might otherwise be outsourced has been critical to the union.

The agreement also offers bonuses of $5,000, or 10% of the previous year's earnings, whichever is greater, in the first year, then $1,500 in each of the second and third years for workers. Boeing's earlier offer had provided an average bonus of $6,400 this year.

"The fight for job security is something we battle every contract, every opportunity and every day," said IAM district president Tom Wroblewski, in a prepared statement. "In this round, we won the battle and made some significant gains. In the fight for job security, we won. "

In a prepared statement, Scott Carson, CEO of Boeing Commercial Airplanes, said: "This is an outstanding offer that rewards employees for their contributions to our success while preserving our ability to compete."

"Both sides are claiming a level of success," said Bank of America analyst Harry Nourse, in a report, noting that Boeing says it has maintained flexibility, while the IAM says the contract provides job security.

Nourse said the strike will impact the fourth quarter's earnings and deliveries of the upcoming 787. Boeing has promised to update its guidance once the strike is settled.

In the meantime, Nourse noted, since the strike began, Boeing shares have fallen 32.8%, while the

S&P 500

has fallen 31.3%.

"Typically, the impending resolution of a strike at Boeing has precipitated a recovery in the stock (and the suppliers), but this usually comes after a period of having underperformed the broader market," he said.

Bank of America has a financial relationship with Boeing that includes providing investment banking services and holding at least 1% of the company's common stock.