Microsoft Corp., the world’s largest software maker, plans to sell $3.75 billion of debt in its first bond offering, taking advantage of its top credit ratings to help fund a share buyback and technology investments.

The sale will be split among $2 billion of 5-year notes, $1 billion of 10-year debt, and $750 million 30-year bonds, according to a person familiar with the offering who declined to be identified because terms aren’t set. The debt is expected to price as soon as today, the person said.