Tech giant Apple reported a 13% decline in its revenue for the second quarter of its fiscal year, the first time revenue has fallen since 2003.

The iPhone-maker posted a revenue of $50.6bn for its second quarter ending 26 March, compared to $58bn in the corresponding quarter a year earlier.

Apple CEO Tim Cook said: "Our team executed extremely well in the face of strong macroeconomic headwinds."

Apple earned 67% of its revenue in the quarter from sales in countries other than the US. Its net income fell to $10.5bn from $13.6bn reported in the corresponding quarter last year.

The tech giant’s iPhone sales fell to 51.2 million, from 61.2 million in the same quarter in 2015. Sales in greater China dropped 26%, a drop which was largely blamed on the world economic slowdown.

However, revenue from services segment rose 20%, even as the other segments showed a decline. It ended the quarter with $233bn in cash and marketable securities.

Apple CEO Tim Cook said: "We are very happy with the continued strong growth in revenue from Services, thanks to the incredible strength of the Apple ecosystem and our growing base of over one billion active devices."

Third quarter predictions from the company have put revenue at between $41bn and $43bn.

On the other hand, social media company Twitter posted a 36% increase in its revenue for the first quarter this year, but lowered its revenue guidance for the second quarter.

Twitter reported revenue of $594.5m, missing expectations of $607.8m. The company lowered its guidance, estimating its revenue to come in the range of $590m to $610m for the April-June quarter.

"Revenue came in at the low end of our guidance range because brand marketers did not increase spend as quickly as expected in the first quarter. We see a clear opportunity to increase our share of brand budgets over time," Twitter said in a statement.

Advertising revenue hit $531m in the quarter, with mobile advertising accounting for 88% of that revenue. The number of average monthly active users on its site went up by 3% to 310 million in the January-March quarter on year-over-year basis.

"We have a strong product roadmap designed to tap into incremental brand-oriented online video budgets, and will deliver additional features for advertisers later this year-including more detailed demographic targeting and verification, and reach and frequency planning and purchasing," the social media company added.

Easing concerns over its growth, global e-commerce major eBay reported an increase in revenue for the first quarter, with revenues up 4% to $2.1bn.

The online retailer posted 1% increase in its GMV or the total value of all goods sold on its platform to $20.5bn in the quarter.

eBay president and CEO Devin Wenig said: "Q1 represents another quarter of solid results, as we continue to position eBay for long-term success."

eBay estimates revenue to come between $2.14bn and $2.19bn for the second quarter.