Leon Black, Chairman, CEO and Director, Apollo Global Management, LLC, speaks at the Milken Institute's 21st Global Conference in Beverly Hills, California, U.S. May 1, 2018. REUTERS/Lucy Nicholson

(Reuters) - Private equity company Apollo Global Management APO.N is in advanced talks to buy Europe's biggest plastics packaging maker RPC Group RPC.L for more than $3.8 billion, the Wall Street Journal reported on Monday.

RPC on Friday extended the deadline to Jan, 23 for Apollo to make a firm offer or walk away.

Citing people familiar with the matter, the Journal said that a deal could be announced as soon as Tuesday.

Private equity has long been attracted to the sector’s reliable cash flow and growing demand from online shopping, with a spate of takeovers by bigger packaging players further spurring their interest.

RPC, which operates in 34 countries, on Monday had a market capitalization of 3.26 billion pounds ($4.2 billion).

The company said in September that it was in talks on a possible sale to Apollo and U.S. private equity firm Bain Capital, with the deadlines to make a firm offer extended repeatedly since then.

The FTSE mid-cap company ended talks with Bain in December.

RPC declined to comment when contacted by Reuters and Apollo could not be reached for comment outside normal business hours.

(This story corrects the market cap in paragraph five)