COLOMBO - Sri Lankan shares closed firmer on Tuesday, led by gains in diversified and banking stocks, while the rupee weakened on higher importer dollar demand.

** The country's benchmark stock index ended 0.42% up at 5,683.47 after slipping from a four-month high on Monday

**The index is down about 6.1% so far this year.

** The country's stock market had a turnover of 339.8 million Sri Lankan rupees ($1.93 million), less than this year's daily average of about 606.5 million rupees so far. Last year's daily average came in at 834 million rupees.

** Foreign investors sold a net 25.8 million rupees worth of shares, but they have been year-to-date net buyers worth 1.47 billion rupees equities so far this year, index data showed.

** Shares of conglomerate John Keells Holdings Plc rose 1.8%, the country's biggest listed lender Commercial Bank of Ceylon ended 1% firmer, and LOLC Holdings Plc climbed 1.5%.

** Meanwhile, the currency ended 0.06% weaker at 176.00/10 per dollar, compared with Monday's close of 175.90/176.00, as importer demand for the greenback outpaced the dollar selling by banks.

** The rupee is up 3.75% so far this year.

** The central bank left key interest rates unchanged on July 11 as expected, after cutting them in May to support the economy as tourism and investment plummeted in the wake of deadly suicide bombings in April.

** Foreign investors bought a net 1.22 billion rupees worth of government securities in the week ended July 17, but the market has seen a year-to-date net foreign outflow to 18.46 billion rupees, the central bank data showed.

($1 = 176.0000 Sri Lankan rupees)

(Reporting by Ranga Sirilal and Shihar Aneez; editing by Uttaresh.V) ((ranga.sirilal@thomsonreuters.com; +94-11-232-5540; Reuters Messaging: ranga.sirilal.thomsonreuters.com@reuters.net ; www.twitter.com/rangaba))