LONDON, June 3 (Reuters) - Saudi Arabia's STC Group is in the early stages of considering an offer for European telecom and pay-TV operator United Group, according to three people with knowledge of the potential deal.

UK buyout group BC Partners, which acquired United Group in 2019 from KKR, is working with advisors on a sale due to start in the coming weeks, two of the people said.

STC has started early stage work on a transaction, which may or may not result in a formal offer, a third person said.

A deal could value United Group around 8 billion euros ($8.7 billion) including debt, one of the people said.

The sources, who requested anonymity as the matter is confidential, cautioned that a deal was not certain and may not happen.

Spokespeople for STC and BC Partners declined to comment.

If STC succeeds with a deal for United, it would further its expansion into the European telecoms sector. Last year the kingdom's largest telecoms operator said it had acquired a 4.9% stake in Spain's Telefonica, with the potential to increase it further to nearly 10%. STC´s subsidiary TAWAL also last year acquired United Group’s telecommunications tower assets in Bulgaria, Croatia and Slovenia.

BC Partners is considering different ways to maximize the value of a sale, including splitting it into different regions, two of the sources said.

The sale has also attracted attention from infrastructure funds interested in bidding for specific countries including Greece, Croatia and Slovenia, according to one of the sources.

Abu Dhabi-based Emirates Telecommunications said in April that it reviewed "relevant market opportunities" but had not entered into any negotiation or agreement to acquire United Group. This followed press reports that it was considering acquiring the European group.

United Group's revenue and earnings before interest, tax depreciation and amortization after leases, a measure of profitability, grew 7% to 2.7 billion euros and 988 million euros respectively last year.

The capital structure of the group includes 4 billion euros of senior secured notes issued by United Group and 300 million euros of payment-in kind notes issued by its parent company Summer Bidco, according to a note published by S&P in January.

($1 = 0.9224 euros) (Reporting by Amy-Jo Crowley, Andres Gonzalez and Hadeel Al Sayegh; editing by Anousha Sakoui and Emelia Sithole-Matarise)