Two major Catholic hospital systems with a big presence across the Southland — Providence Health & Services and St. Joseph Health — want to join forces amid an industrywide consolidation drive.

St. Joseph Health and Providence Health and Services have received regulatory approval for a merger that will create the nation’s third-largest nonprofit health system, officials said Wednesday.

Providence St. Joseph Health, the giant nonprofit health system headquartered in Renton, said Thursday a plan to modernize and consolidate functions such as accounting, human resources and ...