UPDATE 1-Sweden sells part of retail pharmacy monopoly

* Sweden ends long-standing monopoly control of drug sales

* Finland's Oriola-KD Oyj, Sweden's Investor AB among buyers

* Sale is part of plan to roll back state ownership of firms

(Updates with detail, background)

STOCKHOLM, Nov 9 (Reuters) - Sweden auctioned off part of its Apoteket retail pharmacy monopoly for 5.9 billion crowns ($844.5 million) as part of the government's plan to roll back state ownership.

Since coming to power in 2006, the centre-right coalition government has sold several chunks of an extensive corporate empire, including vodka maker Vin & Sprit, real estate firm Vasakronan and part of telecoms operator TeliaSonera (TLSN.ST).

Sweden has also begun to open up the gaming and betting market. However, Swedes continue to have to buy wine and spirits from the state monopoly, Systembolaget.

Apoteket, which serves about 315,000 customers a day, sold 28.4 billion crowns of medicine to private individuals and 3 billion crowns of other merchandise in 2008. Swedes have had to buy their drugs exclusively from the group since 1970.

The government's plan was to sell more than 960 of a total of 916 outlets in a first phase, with another 150 to be sold to small business owners later. The state will keep the remainder.