Verizon Communications has said it would buy Aol in a deal valued at around $4.4bn.
The offer of $50 per share is a premium of 17.4% to Aol's close yesterday of $42.59.
Aol owns a number of online news outlets and services, including The Huffington Post, Engadget and Mapquest.
The company has had operations in Ireland since 1997 and currently employs around 200 people here.
The deal, which includes about $300m of Aol debt, will take the form of a tender offer followed by a merger, with Aol becoming a wholly owned subsidiary of Verizon upon completion.
Verizon said it expects to fund the transaction from cash on hand and debt.
Aol was founded in the early 90s and provided online connectivity and services to US users.
It later merged with Time Warner, but was spun off into an independent company in 2009.