CHICAGO (Reuters) - Public school teachers in Chicago voted overwhelmingly to ratify a new three-year contract, ending a bitter dispute with Mayor Rahm Emanuel over school reforms, the Chicago Teachers Union said late on Wednesday.

The union said 79.1 percent of its members voted in favor of the deal, which will give teachers an average pay raise of 17.6 percent over the life of the contract if it is extended to four years, as well as some improvements in benefits.

By ratifying the contract, the teachers also officially ended their strike against the country's third-largest school district, which was suspended on September 18.

Some 350,000 students in Chicago missed seven days of school as a result of the walkout, the first strike by public teachers in the city in 25 years.

(Reporting by Mary Wisniewski; Writing by James B. Kelleher; Editing by Greg McCune and Jim Loney)