Yahoo's quarterly earnings fell short of Wall Street expectations last night in what may be the company's last financial report before it sells its core business. 

Yahoo reported adjusted earnings of nine cents per share, short of the 10 cents that analysts expected. 

It also announced a $482m write-down on the value of Tumblr, the social media service that it acquired in 2013 for $1.1 billion. 

Yahoo is in the process of auctioning off its search and advertising business, and is expected to choose a winner this week. 

The company said its board has made "great progress on strategic alternatives" but did not comment further on the auction process. 

Verizon Communications and AT&T are said to be in the running to acquire the core business, along with private equity firm TPG Capital and a consortium led by Quicken Loans founder Dan Gilbert and backed by billionaire Warren Buffett. 

Yahoo also owns large stakes in Chinese ecommerce giant Alibaba and Yahoo Japan, which are worth far more than the company's internet business. 

The earnings report showed the continued slide in Yahoo's business during the protracted sale process. 

After the Tumblr write-down, the company posted a net loss of $439.9m, or 46 cents per share, compared with a loss of $21.6m, or 2 cents per share, a year earlier. 

Although total revenue rose to $1.31 billion from $1.24 billion a year earlier, the seeming improvement was the result of a change in the way the cost of acquiring traffic is counted. 

After deducting fees paid to partner websites for traffic, revenue fell to $841.2m from $1.04 billion. 

Revenue in the company's emerging businesses, which chief executive Marissa Mayer calls Mavens - mobile, video, native and social advertising - showed some life, rising 25.7% to $504m in the second quarter ended June 30. 

But the improvement in Mavens was offset by decreases in gross search revenue that is only expected to get worse, analysts said. 

Gross search revenue for the quarter was $765m, down 17% from the same time last year. 

This is supposed to be the growth engine of the company, and at best it was up slightly year over year. 

Analysts said that shows that even in high-growth categories like mobile and native Yahoo are losing their search impact.