July 27 (Reuters) - Twitter Inc failed to add users on a monthly basis in the second quarter, compared with the first quarter, amid fierce competition from Facebook Inc and Snap Inc's fast-growing messaging app Snapchat.
Twitter's shares fell 5 percent in premarket trading on Thursday.
The company's second-quarter net loss widened as it took a $55 million impairment charge and revenue fell 4.7 percent.
Twitter has been trying to boost revenue through live-streaming deals, but suffered a setback in April when it lost a deal to live stream NFL games this year to Amazon.com Inc .
Twitter's average monthly active users was 328 million in the second quarter ended June 30. Analysts were expecting 328.8 million, according to financial data and analytics firm FactSet.
Monthly active users is a key performance indicator for social networking services - typically calculated by taking the number of users who have logged in and logged out during the 30-day period.
Advertising revenue fell 8 percent to $489 million, but came in well ahead of the $458.1 million estimate.
"Until Twitter can return to revenue growth, we expect advertisers to devote their ad budgets to platforms with better targeting, reach, and scale," Wedbush analyst Michael Pachter wrote in a pre-earnings note.
The company's net loss widened to $116.5 million, or 16 cents per share, in the second quarter ended June 30, from $107.2 million, or 15 cents per share, a year earlier.
Excluding items, the company earned 8 cents per share.
Revenue fell about 4.7 percent to $573.9 million, the second time it has fallen since Twitter's debut in 2013. (Reporting by Pushkala A and Aishwarya Venugopal in Bengaluru; Editing by Saumyadeb Chakrabarty)