Sky and CVC announced the deal in December, which values the online betting business at 800 million pounds. Sky, which has 20 million customers in Britain, Italy, Germany, Austria and Ireland, will receive 600 million pounds in cash at completion and will retain a stake of around 20 percent in Sky Bet.

Goldman Sachs is expected to lead the debt financing which is due to launch for syndication to institutional investors, with a bank meeting due to take place week commencing Jan.12. Other banks are likely to join the deal prior to the bank meeting, the sources said.

The financing comprises 340 million pounds of first lien loans and 50 million pounds of revolver, the sources said.

Leverage on the deal totals 5.25 times, the sources added.

Sky Bet, the title sponsor of English soccer's Football League, generated profit before tax of 50 million pounds in the year to June 30, 2014, on revenues of 182 million pounds. Founded in 2001, the company operates sports betting and gaming sites in the growing online market.

(Editing by Christopher Mangham)

By Claire Ruckin