Spanish telecoms giant Telefonica reported on Friday a 1.9-percent slip in net quarterly profit to 1.624 billion euros ($2.3 billion), but gave no explanation.
The outcome was below the average figure of 1.72 billion euros expected by analysts as polled by Dow Jones Newswires.
Data from the company indicated that the setback reflected an increased tax charge, increased financial charges and a negative contribution from holdings in other companies.
Telefonica is the second-biggest company in the European telecoms sector in terms of capitalisation.
Sales rose by 10.8 percent from the equivalent figure for the first quarter of last year to 15.435 billion euros.
Operating income before amortisations rose by 9.0 percent to 5.574 billion euros and the operating outcome by 4.3 percent to 3.057 billion euros.
Company president Cesar Alierta said that the trend of the results in the first quarter supported the group's targets for the whole year.
Telefonica said in February that it was targeting an increase in sales this year of up to 2.0 percent. It said that 71.0 percrent of sales were now generated outside Spain, and that growth had been particularly strong in Brazil.
In April, the group said it intended to shed 20 percent of its staff in Spain, or about 6,000 people, owing to a fall of sales in the country where it is the biggest telecom service provider.