WASHINGTON (AP) -- The National Labor Relations Board has approved rules that could give labor unions a boost in organizing new members.

The rules are expected to speed the pace of union elections by simplifying procedures and reducing delays. That could help unions make inroads at businesses such as Target and Wal-Mart, which have successfully resisted union organizing for years.

Unions say the old rules allowed companies to file frivolous appeals, holding up elections for months or years. But business groups claim the new plan will allow "ambush" elections that don't give company managers enough time to respond.

Labor board chairman Mark Pearce said Wednesday that the rules give employees who want a union the right to vote in a timely manner without being hampered by needless litigation.