Two of Britain's best-known drinks brands, Lucozade and Ribena, are reported to be a £1billion takeover target for the owner of Irn-Bru.

AG Barr, which recently failed to pull off a deal with Britvic to create Europe's largest soft drinks company, is expected to open talks with private equity firms with a view to launching a joint bid for the brands.

Drugs giant GlaxoSmithKline is selling Lucozade and Ribena as it believes the brands would be worth more to a larger drinks business.

Interest is expected from a number of private equity firms, although the Japanese drinks manufacturer Suntory is believed to be the favourite as it looks to add to a portfolio that already includes Orangina Schweppes.

Cumbernauld-based Barr, which dates back to 1875 and also makes Tizer and Rubicon, is considering whether to team up with the buy-out firms Blackstone and Lion Capital.

Last week, it tabled a new proposal to rival Britvic following formal notification that their £1.4 billion merger had been given the all-clear from regulators.

But Robinsons squash firm Britvic turned down the offer even though it was on "more favourable terms".

Ribena and Lucozade are largely sold in Western markets and earn about £600million a year.

They are made in the UK at a factory in Coleford, Gloucestershire, and are also produced in Nigeria and Kenya.

They were owned by Beecham prior to its merger with SmithKline, with Lucozade dating back to 1927 and Ribena starting a few years later.

Glaxo is expected to launch an auction for the brands in the autumn.