Verizon Communications Inc. has agreed to pay $4.8 billion to acquire Yahoo Inc., according to a person familiar with the matter, ending a drawn-out auction process for the beleaguered internet company.

The price tag, which includes Yahoo’s core internet business and some real estate, is a remarkable fall for the Silicon Valley web pioneer that once had a market capitalization of more than $125 billion at the height of the dot-com boom.

...