Illumina Inc. intends to offer about $900 million in convertible senior notes, and plans to use the balance of the net proceeds for general corporate purposes.

It proposes to offer $450 million of the convertible senior notes to be due in 2019 and the other $450 million due in 2021. It also intends to grant initial purchasers a 30-day option to buy an additional $67.5 million in aggregate and another $67.5 million due 2021, bringing the total potential offering up to $1.04 billion.