Mozilla has announced that its new Firefox 3.0.11 browser was downloaded 150 million times during the first 24 hours of becoming available.

The impressive figures followed a statement from Apple recording just 11 million downloads of its new Safari 4 browser in three days.

"I just read that Apple is reporting 11 million Safari 4 downloads in just three days. That's pretty amazing. I'd like to follow up that report with one of my own," said Asa Dotzler, director of community development at Mozilla, in a blog post before boasting of the record number of Firefox downloads.

It is likely that both companies included automatic updates in the download figures. This is when the latest version of a browser is pushed out to users via an update tool.

Firefox 3.0.11 was released on 11 June and is mainly a security and stability update. The update builds on the major Firefox 3 browser launch in June last year, which had eight million unique downloads on the first day, setting a new Guinness World Record.

Among the new features in the Safari 4 browser, which was released on 8 June, are the ability to view history files in the iTunes 'cover flow' style, and improved archiving of browsing history. The update also fixes 51 security flaws.

Headlining the Safari 4.0 release, however, is the new Nitro JavaScript engine. The company said that the new engine significantly improves JavaScript performance and could get even faster when the company releases the 64-bit OS X Snow Leopard update later this year.

Apple said the engine will execute JavaScript nearly eight times faster than Microsoft's Internet Explorer 8 and more than four times faster than Firefox 3.

Internet Explorer continues to dominate the global browser market, followed by Firefox and then Safari.