* GSK keen to acquire privately owned Ache -sources
* Novartis, Pfizer, Abbott also likely to be interested
* Sale by Lazard could value firm at $3-4 bln or more
* Ache owners' rift makes outcome of process uncertain
By Ben Hirschler and Nadia Damouni
LONDON/NEW YORK, Feb 8 (Reuters) - Britain's GlaxoSmithKline is one of several groups exploring a potential takeoverof Ache Laboratorios Farmaceuticos, one of Brazil's biggestdrugmakers, people familiar with the matter said.
The privately owned business is attractive to a number ofdrug companies looking to increase their footprint in LatinAmerica and could fetch $3-4 billion, or even more ifcompetition is keen, they added.
"It's something Glaxo has looked at in the past and they'vebeen knocking on the door," said one source.
Other drugmakers likely to be interested include Novartis, Pfizer and Abbott Laboratories, othersources said.
Officials for all four multinational companies declined tocomment. Ache also declined to comment on whether the groupwould be sold.
Sources said last week that investment bank Lazard had beenmandated by key shareholders to investigate a sale, althoughwhether a deal will go ahead is still uncertain given divisionsamong the families controlling the company.
The Baptista and Siaulys families, who hired Lazard, areready to sell up but the Depieri family would like to hold on toits stake.
Lazard officials declined to comment on the bank's role inthe process.
Although it ranks fourth in terms of overall Brazilian drugsales, Ache is the leader in prescription medicines and is alsoactive in the fast-growing over-the-counter (OTC) business,where there is keen competition for assets.
Britain's Reckitt Benckiser agreed on Tuesday to payBristol-Myers Squibb $482 million to get its hands on anumber of top-selling OTC remedies in Brazil, Mexico and otherparts of Latin America.
The U.S. drugmaker is less interested in OTC products inemerging markets than bigger rivals like GSK and Pfizer.
Ache's earnings before interest, tax, depreciation andamortisation (EBITDA) were 540 million reais ($270 million) inthe year to Sept. 30. 2012, on sales of 1.5 billion reais, andthe company's market position is strong, according to a reportlast month by Fitch Ratings.
Assuming earnings for the current year of some $300 million,a price of $3 billion to $4 billion would be in line withcurrent valuations for emerging market drug companies of a low-to mid-double digit multiple of EBITDA, sources said.