COLOMBO - Sri Lankan shares jumped more than 1% on Wednesday to hit their highest close in nearly 20 weeks, led by gains in banking and diversified stocks, while the rupee weakened on higher importer dollar demand.

** The country's benchmark stock index ended 1.1% up at 5,745.97 its highest close since March 7.

**The index is down about 5.06% so far this year.

** The country's stock market had a turnover of 1.1 billion Sri Lankan rupees ($6.25 million), well above this year's daily average of about 610.1 million rupees so far. Last year's daily average came in at 834 million rupees.

** Foreign investors bought a net 362,201 rupees worth of shares, extending year-to-date net buying to 1.47 billion rupees worth of equities so far this year, index data showed.

** Shares of Sri Lanka Telecom Plc jumped 3.9%, Sampath Bank Plc rose 4.6%, conglomerate John Keells Holdings Plc climbed 1.2% and the country's biggest listed lender Commercial Bank of Ceylon ended 2.5% firmer.

** Meanwhile, the currency ended 0.06% weaker at 176.10/25 per dollar, compared with Tuesday's close of 176.00/10, as importer demand for the greenback outpaced the dollar selling by banks.

** The rupee is up 3.69% 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 = 176.1000 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))