* Foreign investors buy Keells; net inflow at 64.2 mln rupees
* Rupee steady despite heavy importer demand
COLOMBO, Oct 27 (Reuters) - Sri Lanka's stock market fell to a one-week low on Thursday in thin volumes with turnover slumping to a near two-year low as many investors were on the sidelines, awaiting direction in an oversold market while foreign investors bought shares.
The island nation's main share index fell 0.35 percent or 22.46 points to 6,323.59, lowest since Oct. 20.
Turnover was at 533.8 million Sri Lanka rupees ($4.8 million), lowest since Dec. 14, 2009, and well below last year's average of 2.4 billion and this year's 2.6 billion.
The bourse witnessed a net foreign inflow of 64.2 million rupees on Thursday and thus far in 2011, offshore investors have sold 17 billion, and a record 26.4 billion in 2010.
The bourse has fallen 6.8 percent this month alone. It slipped to Asia's sixth-best performer with a year-to-date loss of 4.71 percent after being on the top for most of 2011 and in 2009 and 2010.
Hva Foods fell 1.66 percent. It gained 33.8 percent during a rally on Friday and Monday over speculation the director general of the Securities and Exchange Commission was being forced out. The regulator has denied the rumours.
Conglomerate John Keells Holdings which saw foreign buying of 273,441 shares, ended 0.26 percent firmer at 190.50 rupees.
On Thursday, the bourse was in oversold territory, with the relative strength index falling to 28.83 from Tuesday's 29.88, below its lower neutral range of 30.
Losers outperformed gainers by 133 to 52 on Thursday, Thomson Reuters data showed.
Thursday's total volume was 34.3 million, lowest since April 11, against a five-day average of 54.3 million. The 30-day and 90-day average trading volumes were 86.5 million and 109.8 million. Last year's daily average was 67.9 million.
The rupee closed flat at 110.18/20 a dollar for a 19th straight day, as a state bank continued dollar sales at 110.20 rupees amid strong importer dollar demand, dealers said.
The stock and foreign exchange markets were closed on Wednesday to mark the Deepavali festival.
FACTORS TO WATCH: - If the central bank can maintain a narrow dollar trading range - How much the central bank buys in repo auctions - Rupee depreciation due to heavy importer dollar demand
http://www.reuters.com/article/2011/10/27/markets-srilanka-idUSL3E7LR1WE20111027