Sky presses ahead with O2 takeover as financial results show 40,000 broadband customers were lost between January and March.
O2 has lost a record number of broadband customers since the start of 2013.
The company's latest financial results show 40,700 customers cancelled their O2 broadband service during the first three months of the year.
It follows the announcement at the start of March that rival provider Sky would purchase the O2 broadband and home phone business - as well as its sister company BE Broadband - in a takeover deal worth up to £200million.
O2 has shed over 150,000 broadband customers since peaking at 671,000 subscribers in December 2010. During that time, many customers became frustrated by O2's lack of a 'superfast' option and switched to rival providers such as BT and Virgin Media.
The figures show there were 519,000 O2 broadband customers at the end of March.
Meanwhile, Sky, which has more than 4.2 million broadband customers of its own, has now officially completed its takeover of O2 and BE Broadband.
This means all O2 and BE Broadband customers will be gradually migrated to Sky's broadband network. The migration process begins later this year and is expected to take several months.