PITTSBURGH — PNC Financial Services Group is buying a historic former Mellon Bank building in downtown Pittsburgh with plans to move 800 employees there in administrative offices.

Mellon Bank built the stately granite structure in 1923 but it was closed, sold and converted to a Lord & Taylor Department store in 2000.

The city spent nearly $12 million to lure Federated Department Stores to the site, but it closed four years later when it failed to attract shoppers and has been vacant since.

PNC officials say the workers will be relocated from other spaces in and around the city.