AMSTERDAM—Dutch electronics group Philips NV said Tuesday it would split itself into two companies, spinning off its iconic lighting business 123 years after making its first incandescent light bulb.

It's the latest in a series of restructuring moves for the Dutch conglomerate, amid consecutive profit warnings and criticism its cumbersome corporate structure is slowing it down. Philips said it would merge its health-care and consumer-electronics divisions into a single company, which will remain the core of Philips's business....