MUMBAI, India - aims to double the total value of goods it sells to $8 billion this year, two people with knowledge of the plans said, as India's largest online marketplace seeks to widen the gap with rivals including Amazon.com's India unit.

Online retailers often use GMV, or gross merchandise value based on monthly online sales, as a measure of performance, as they typically make revenues from the commissions they get from sellers.

Flipkart's current GMV is $4 billion, the sources said, declining to be named as they were not authorised to speak to the media. They did not give further details.

Industry executives estimate Snapdeal and Amazon's India arm notch up GMVs of around $3 billion and $1 billion respectively.

Online retailing is growing at a breakneck pace in India, which has the world's third-largest population of Internet users even with only a fifth of its population online.

Consulting firm Technopak estimates the Indian e-tailing market will be worth $32 billion in 2020, more than 10 times its value of $2.3 billion in October last year.

Flipkart aims to ship one billion units a month and to serve 100 million customers by 2018 fiscal year, according to company executives who attended a recent townhall meeting. Currently the company ships around 8 million units a month.

Industry sources value Flipkart, founded in 2007, at around $11 billion.

$1 = £0.65