No financial terms of the deal were disclosed, but local media reports valued TPG's purchase at 150 million pounds.

Poundworld, which started in 1974 as a market stall in Wakefield in West Yorkshire, has grown to over 280 UK stores, as well as 50 multi-priced Bargain Buys shops, on rising demand for discounters that has also supported the likes of supermarkets Aldi and Lidl.

TPG will inject new equity capital to fund a quicker store rollout and invest in new distribution facilities, Poundworld said, adding its founder and boss Christopher Edwards and other senior executives would retain a minority stake in the firm.

"I began this business as a market trader and we now have millions of customers from all corners of the nation and all walks of life. Still, there is so much more for us to achieve," Edwards said on Thursday.

In February, Poundland agreed a 55 million pound deal to buy rival 99p Stores, but the deal is undergoing a review by Britain's competition watchdog.

(Reporting by Neil Maidment; editing by Susan Thomas)