* Q4 loss 180 mln riyals vs 66 mln yr ago
* Annual loss 465.7 mln riyals vs 215.8 mln yr ago
* Says has decided to cut workforce by 10 pct
* Chairman quits due to other work commitments (Recasts, adds details)
By Matt Smith
DUBAI, May 17 (Reuters) - Vodafone Qatar plans tocut its workforce by a tenth, it said on Tuesday, as it reporteda sixth straight widening quarterly loss citing competition andwaning international call usage.
The Vodafone Group affiliate has yet to make aquarterly net profit since ending state-controlled Ooredoo's domestic monopoly in 2009, but appeared close tobreaking even in mid-2014.
Since then, however, Ooredoo has fought back, cutting pricesto woo back customers and defend its market share.
Vodafone Qatar's fourth-quarter loss nearly tripled from ayear earlier to 180 million riyals ($49.5 million) for the threemonths to March 31 versus 66 million a year earlier.
Vodafone Qatar's financial year starts on April 1.
The company's net loss for the 2015-16 financial year was465.7 million riyals versus 215.8 million the previous year.
Mobile average revenue per user (ARPU), a key industrymetric, for the 12 months to March 31 fell 13 percent to 107riyals.
In Tuesday's bourse statement the company also announcedthat Sheikh Khalid Bin Thani al-Thani had quit as chairman dueto other work commitments. Rashid al-Naimi has been appointedacting chairman.
"The past year has been difficult for the company with theimpact of structural changes in our industry, namely theincreasing use of data at the expense of international voicetraffic and sustained price competition," Naimi said in thestatement.
This has severely impacted Vodafone's revenue performance,he added, with these difficulties prompting the company torecently decide to cut its workforce by 10 percent. Thecompany's statement did not state when these layoffs wouldbegin.
International calls had been especially lucrative fortelecom operators in the Gulf, which is home to large expatriatepopulations. But internet-based messaging and callingapplications such as Skype and Whatsapp, which offer free orlow-cost communication, have hurt this revenue stream.
Vodafone Qatar, 23 percent owned by Vodafone and 22 percentby state-run Qatar Foundation, also said it would not pay adividend for 2015-16. It had paid a cash dividend of 0.21 riyalsper share for the 2014-15 financial year, Reuters data shows.
($1 = 3.6398 Qatar riyals) (Reporting by Matt Smith; editing by Jason Neely)