BUDAPEST (Reuters) - Niklas Zennstrom, co-founder of Internet telecoms group Skype, said on Tuesday that the business, bought by EBay, had not performed as well as anticipated in the short term.

"We had to chart the trajectory of growth and how fast that would run, (but) we found out that was a bit front-loaded," Zennstrom told the annual ETRE technology conference in Hungary.

"We overshot in terms of monetisation," he said.

EBay said last week it would cut as much as $1.2 billion off the $4.3 billion potential price it agreed to pay for Web-based phone-calling service Skype two years ago.

The writedown on the value of the deal came as eBay said Skype co-founders Niklas Zennstrom and Janus Friis had resigned as executives, and marked a tacit admission of lackluster returns from Skype since eBay acquired it two years ago.

EBay said it had paid $530 million to Skype shareholders, including Zennstrom.