Yahoo is touting nearly 3,000 patents in an auction that is estimated to bring in over $1 billion to the company that has yet to turn itself around in this competitive market despite the hiring of Marissa Mayer four years ago.

“Yahoo is exploring the divestiture of a portfolio of more than 3,000 patents and pending applications covering a wide range of technology, including early-filed Internet search, advertising, and cloud technology,” a Yahoo spokeswoman said. “This represents a unique opportunity for companies operating in the internet industry to acquire some of the most pioneering and foundational patents related to web search and advertising,” the company stated.

Over 2,500 of these patents were assigned to a Yahoo subsidiary, Excalibur, ahead of the sale in April.  Many saw this as the beginning of the sale, which coincidently, occurred on the same day as the first-round bid deadline in the auction for Yahoo’s core  business.

Back in February Yahoo said it was exploring divesting nonstrategic assets, including patents and real estate, which is said to generate an estimated $1 billion to $3 billion in cash this year. In the past three years they have already collected $600 million from patent sales and licensing fees.

Although they are selling nearly 3,000 patents, the company will also be selling a significant number of patents and pending applications that relate to its core internet business. Five hundred US patents and over 600 US pending applications are considered “necessary” to the backbone and infrastructure of Yahoo.

It is unclear how many parties are interested in the patents. Yahoo has invited strategic buyers, private-equity firms, and investment firms focused on intellectual property to submit bids.  Alphabet Inc. and Microsoft Corp. are among the most obvious potential buyers at this time. Yahoo’s enforceable patents are said to have an estimated value of $965 million to $1.34 billion.