* GSK weighing disposal of established drugs in Western markets
Part of wider reshaping of British drugmaker's business
* GSK said in "no rush" to divest older non-core assets
(Adds details on private equity firms, Lazard advising GSK, background)
By Ben Hirschler and Freya Berry
LONDON, May 29 (Reuters) - GlaxoSmithKline has invited private equity firms to consider making offers for a range of its older drugs sold in Western markets, according to three people with direct knowledge of the matter.
The move is part of a reshaping of the drugmaker's business, which also involves a major asset swap deal struck last month with Novartis.
Chief Executive Andrew Witty said last month that Britain's biggest pharmaceuticals company could dispose of individual medicines or a broader portfolio of older established products.
A GSK spokesman had no further comment on the potential disposals on Thursday.
Private equity firms approached by GSK include Advent International, Blackstone and KKR, the sources said, and the drugmaker is being advised by Lazard. Officials at Lazard and the three private equity firms declined to comment.
GSK said at its first-quarter results on April 30 that it was evaluating options to "maximise the value of our portfolio and currently reviewing our Established Products Portfolio".
The company started breaking out results for the portfolio of older medicines for the first time this year as a prelude to a potential divestment of at least some of them.
However, one person familiar with GSK's thinking said it was in "no rush" to dispose of the 50 or so older medicines in the division and it also planned to retain rights to most of the products in emerging markets, where they form an important part of GSK's business.
Sales of established products totalled 814 million pounds in the first quarter of 2014, down 11 percent on a year earlier, reflecting increased competition from cheaper generic copies. Around half of those sales were made in emerging markets.
GSK has already disposed of some non-core products, having agreed last September to sell thrombosis medicines Arixtra and Fraxiparine to South Africa's Aspen Pharmacare for 700 million pounds ($1.2 billion), or around two times their annual sales.
The drugmaker's approach to private equity firms was first reported by Sky News.
($1 = 0.5982 British Pounds)
(Additional reporting by Anjuli Davies; editing by Jon Boyle and Pravin Char)