Japanese tyre maker Bridgestone said Tuesday its first-half net profit jumped 39.1 percent year-on-year, partly driven by a recovery in domestic demand after last year\'s quake-tsunami disaster. Earnings in the six months to June reached 75.27 billion yen ($965 million), Bridgestone said, despite rising raw material costs and the strong yen, which makes exporters\' products more expensive abroad. Sales in the period rose 2.0 percent to 1.49 trillion yen from a year earlier, it said. Also Tuesday, Bridgestone upgraded its earnings outlook for the year to a net profit of 172 billion yen from earlier forecast of a 168 billion yen profit. But sales in the year were expected to come in at 3.13 trillion yen, down from the 3.24 trillion yen forecast previously. Bridgestone reports its results on a calendar-year basis, unlike many Japanese firms which operate on a fiscal year model to from April to March. The company, which competes with France\'s Michelin for top spot in global tyre sales, said its results were helped by strength in emerging markets and rising demand for speciality tyres used in mining and construction, despite a weaker European market and surging Japanese currency. Demand linked to reconstruction in Japan\'s disaster-struck northeast also boosted the latest results, Bridgestone said.