Twitter has lost almost half of its advertising revenue since it was bought by Elon Musk for $44bn (£33.6bn) last October, its owner has revealed. He said the company had not seen the increase in sales that had been expected in June, but added that July was a "bit more promising". Mr Musk sacked about half of Twitter's 7,500 staff when he took over in 2022 in an effort to cut costs. Rival app Threads now has 150 million users, according to some estimates. Its in-built connection to Instagram automatically gives the Meta-designed platform access to a potential two billion users. Meanwhile, Twitter is struggling under a heavy debt load. Cash flow remains negative, Mr Musk said at the weekend, although the billionaire did not put a time frame on the 50% drop in ad revenue. In a tweet he said: "Need to reach positive cash flow before we have the luxury of anything else." The development is the latest sign the aggressive cost-cutting measures have not been enough to ignite a return of advertisers who fled after changes to its content moderation rules.