Scott Olson / Getty Images, file

Chicago Teachers Union (CTU) delegates embrace after voting to end their strike on September 18, 2012 in Chicago, Illinois.

Members of the Chicago Teachers Union have overwhelmingly ratified a new contract, union officials said late Wednesday, ending a bitter dispute with Mayor Rahm Emanuel over school reforms that prompted the first strike of city teachers in 25 years.

The deal will give teachers an average pay raise of 17.6 percent over four years if the three-year contract is extended an extra year.

The pay increases would cost an extra $74 million a year, the district has said. Chicago teachers make an average of about $76,000 annually, according to the school district.

In addition to the pay raises, the deal establishes for the first time an evaluation system for teachers that is based in part on student performance on standardized tests. It also gives principals more authority to hire teachers for their schools and extends the length of the school day. 

Scott Olson / Getty Images, file

Mayor Rahm Emanuel greets students as they arrive for school at Frazier International Magnet School on September 19, 2012 in Chicago, Illinois.

The union got guarantees that any teachers laid off will have preference to be rehired by the district, and Emanuel dropped a demand that teacher pay be tied to merit. 

A statement from the CTU said 79.1 percent of the 20,765 votes cast by teachers, paraprofessionals and school clinicians were in favor of the contract, put before them on Tuesday. Ratification required a majority vote in favor.

“This shows overwhelming recognition by our members that this contract represents a victory for students, communities and our profession,” CTU President Karen Lewis said. “Our members are coming are coming out of this with an even greater appreciation for the continued fight for public education.  We thank our parents for standing with their children’s teachers, paraprofessionals and clinicians.”

Read more from NBCChicago.com

Members of the Chicago Board of Education must also vote approve the contract before it becomes effective. That vote is expected Oct. 17, and approval seems likely.

Biggest losers of Chicago's teachers strike? The students, critic says

"I am pleased that the members of the CTU have ratified this contract, and we can now demonstrate to our students that even when two sides start far apart, they can find common ground and reach a resolution. It’s an incredibly important message to send," Chicago Board of Education President David Vitale said in a statement.

Thousands of teachers in the nation's third-largest school district walked off the job on Sept. 10 after more than a year of slow, contentious negotiations over salary, health benefits and job security.

Students were kept out of classes for seven days before CTU's members voted to end the work stoppage.

Chicago teachers agree to end strike, classes to resume

Fitch Ratings earlier this week downgraded the Chicago Board of Education's debt rating, citing the school system's increased budget pressures in the wake of the deal.

This followed a downgrade by Moody's Investors Services last week and could mean the district pays higher interest rates on any debt issues. 

Reuters contributed to this report.

More world stories from NBC News:

• From war zones, photographer brings scars and searing images
• Images: Inside Syria with Ann Curry
• NBC's Lester Holt answers your questions about Afghanistan
• After 7 rhinos slaughtered, India looks to one from same fate
• Colonial sins return to haunt former world powers
• Death threats force Afghan actress into hiding
• In Iran, sanctions bite and currency collapses
• Stay informed: Sign up for our newsletter

Follow World News from NBCNews.com on Twitter and Facebook

Getty Images stock

One of the most common complaints is workers who fail to get overtime pay as required by law.

There’s a simple workplace axiom: You put in your hours and get paid for them. Alas, this doesn’t always happen.

There’s been a record spike in wage and hour violation claims by employees thanks to sustained tough economic times, an increase in enforcement by the government, and confusion over -- or disregard of -- overtime pay provisions.

Seyfarth Shaw

Wage and hour lawsuits have been soaring, according to federal judicial caseload statistics.

Already this year, there have been a record number of lawsuits filed under the Fair Labor Standards Act, which covers wage and hour provisions, with 7,064 filed so far this year. That's up from 7,006 filed for all of 2011 and just 2,035 cases filed a decade ago, according to data compiled by employment law firm Seyfarth Shaw.

The Department of Labor's wage and hour division collected a record $224 million in back wages from employers in the latest fiscal year for more than 275,000 workers.

“Many workers still have a hard time taking advantage of their legal protections,” said Jeffrey Michael Hirsch, associate professor at the University of North Carolina’s law school and a contributing editor to the Workplace Prof Blog.  “Low-wage employees, in particular, often don't earn enough to attract attorneys, although class actions might help in some cases, so you see a lot of cases of unremedied wage theft.”

In those cases, he said, the Labor Department sometimes gets involved, especially to "send a message to employers."

The Labor Department, which sees 125 to 150 cases annually, has stepped up its efforts and pursues litigation when it cannot settle out of court, said Sonia Melendez, a spokeswoman for the agency.

“The wage and hour division has stepped up enforcement efforts on behalf of vulnerable workers — such as low-wage workers, migrant or seasonal laborers, workers with limited English language skills and workers who are unaware of their rights or are reluctant to file a complaint when subject to labor violations,” she said.

The bulk of wage and hour lawsuits deal with  misclassification of employees, alleged uncompensated ‘work’ performed off the clock and miscalculation of overtime pay, said Richard Alfred, an attorney and chairman of Seyfarth Shaw's wage and hour litigation practice.

He attributes the rise in lawsuits to: 

• Weakness of the economy, resulting in layoffs
• Outdated federal and state laws, which have failed to keep up with changes in technology
• A lack of clarity in existing law, making it difficult to classify which workers need to be paid for overtime
• Potential for lucrative recovery by plaintiffs and their attorneys

High-profile cases, such as a wage and hour case involving Wal-Mart, have gotten many employees, employers and lawyers to stand up and take notice.

In May, Wal-Mart agreed to pay nearly $5 million in back wages and damages to more than 4,500 employees who were misclassifed as being exempt from overtime rules. That paled in comparison to the $352 million the company paid in 2008 to settle allegations it didn't provide workers with proper rest and meal breaks but served notice that the Labor Department is paying close attention.

“Misclassification of employees as exempt from FLSA coverage is a costly problem with adverse consequences for employees and corporations,” said Secretary of Labor Hilda Solis at the time of the announcement. “Let this be a signal to other companies that when violations are found, the Labor Department will take appropriate action to ensure that workers receive the wages they have earned.”

Massive monetary awards have increased the profile of such cases, making them attractive to some lawyers, Hirsch said. But he said the awards also have made smart employers more careful. "One thing a lot of management-side firms do is perform internal audits for clients to make sure there aren't problems, particularly with overtime classifications," he said.

Not everyone is as focused on the issue, he added. “I'd like to think that employers of low-wage workers are getting the message, but I'm not sure that's the case in general. You still hear about violations all the time.”

More money and business news:

• Retailers, lawmakers revive call for Internet sales tax
• Think you know how to save? She was a 1940s phenom
• Anger management: This economy breeds rivalries at work
• Video: Drought will cause meat prices to spike next year
• Sign up for our Business newsletter

Follow NBCNews.com business on Twitter and Facebook