Netflix subscriber growth missed its mark in the first quarter of this year, unsettling investors despite strong earnings figures released last night.

The US-based on-demand television service reported a net increase of 4.95m subscribers, most of those overseas where it has been investing in becoming a global entertainment network.

In comparison, Netflix gained 7.05m subscribers in the prior quarter, raising expectations in the market.

"We have come to see these quarterly variances as mostly noise in the long-term growth trend and adoption of internet TV," Netflix said in a letter released along with the earnings figures.

The company expected it would add about 8.15m subscribers overall during the first half of this year as compared with 8.42m in the same period in 2016.

Netflix shares fluctuated in after-market trades that followed release of the quarterly earnings figures, remaining near the closing price of $147.25, which showed a gain for the day.

Netflix reported profit of $178m on revenue of $2.64 billion in the first three months of this year as compared with net income of $28m on revenue of $1.96 billion in the same period a year earlier.

The company described the opportunity for its service as "gigantic" and said it planned to continue investing in films and shows tailored to win fans in countries around the world.

"With a growing member base spread across the world, we seek to please diverse tastes with a wide breadth of content," Netflix said.

Netflix planned to spend a billion dollars this year on marketing aimed at attracting members.