In their struggle to rise above a rundown economy, Britain's major industrial companies have moved into a flurry of mergers. Since last summer, consolidations have created Europe's largest steel company, second-largest auto producer and third-largest electrical-equipment manufacturer. Now the trend has spread into the once staid realm of banking. In the largest bank merger in Britain's history, Westminster Bank, the country's fourth largest (deposits: $4.2 billion), has just agreed to join forces with the fifth-largest, National Provincial Bank (deposits: $4.1 billion).
The combine, for which neither a name nor a boss has...