Yahoo CEO Marissa Mayer welcomes twin girls

A day after Yahoo announced plans to spin off its core internet business, CEO Marissa Mayer has announced she's given birth to identical twin girls.

"Zack and I are excited to announce that our identical twin girls were born early this morning. Our whole family is doing great!" Mayer said in a tweet on Thursday.

The names and weights of the girls were not released.

In September, Mayer announced the impending birth, saying she would take "limited time away" from her post as CEO after working throughout her pregnancy.

She took just two weeks of leave after giving birth to son Macallister three years ago.

Will hold onto Alibaba

On Wednesday, Yahoo announced it was scrapping plans to spin off its stake in Chinese e-commerce firm Alibaba and would instead place its core internet business in a holding company.

Investors had pressured for the move after Yahoo failed to get permission from the IRS for tax relief in selling off the Alibaba stake.

Yahoo's board spent last week in likely tense board meetings to decide the future of Yahoo, a pioneer of the web that has failed to reinvent itself in the smartphone age.

Mayer has been under pressure to restore its internet business for the past three years, without much success. Earlier this year, there were rumours she might be ousted, and this week, Yahoo is mulling plans to shut down more money-losing divisions.

In the latest quarter, revenue in mobile, native video and social ads grew 43 per cent, while overall revenue declined by five per cent, disappointing investors. Yahoo's operating income fell 41 per cent to $92 million in the quarter, and restructuring costs continue to rise.

Yahoo runs several web properties including Flickr, Yahoo Finance, blogging platform Tumblr and fashion site Polyvore, as well as the messenger, mail and search functions it is known for.