Teachers and professional staff of Delaware Valley Charter High School in the Logan section of the city voted, 30-18, yesterday to unionize, the American Federation of Teachers Pennsylvania announced.

Delaware Valley staffers said they wanted to have a greater voice in the decisions made at the school, including those to improve discipline and teacher retention.

The president of the charter's board could not be reached for comment. The city has 67 charter schools. With yesterday's balloting, Delaware Valley becomes the third in the city where teachers are represented by the federation. - Martha Woodall