* Dollar weakens further after weaker jobs data * Aussie hits nearly 3-yr high, sterling reaches $1.40 * Euro rebounds, aided by strong factory survey data * Graphic: World FX rates tmsnrt.rs/2RBWI5E (Adds new quote, chart, latest prices) LONDON, Feb 19 (Reuters) - The Australian dollar rose to near a three-year high and the British pound scaled $1.40 for the first time since 2018 on optimism about economic rebounds in the two countries and after the U.S. dollar was knocked by disappointing jobs data. The U.S. currency had been rising in recent days as a jump in Treasury yields on the back of the so-called reflation trade drew investors. But an unexpected increase in U.S. weekly jobless claims soured the economic outlook and sent the dollar lower overnight. On Friday it traded down 0.3% against a basket of currencies, with the dollar index at 90.309. The Aussie rose 0.8% to $0.784, its highest since March 2018. The currency, which is closely linked to commodity prices and the outlook for global growth, has been helped by a recent rally in commodity prices. The New Zealand dollar also gained, and was not far off a more than two-year high, while the Canadian dollar rose too. Sterling rose to $1.4009 on Friday, an almost three-year high amid Britain’s aggressive vaccination programme. Given the size of Britain’s vital services sector, analysts say the faster it can reopen the economy, the better for the currency. Sterling was also helped by better-than-expected purchasing managers index flash survey data for February. The U.S. dollar has been weighed down by a string of soft labour data, even as other indicators have shown resilience, and as President Joe Biden’s pandemic relief efforts take shape, including a proposed $1.9 trillion spending package. Despite the recent rise in U.S. yields, many analysts think they won’t climb too much higher, limiting the benefit for the dollar. “Our view remains that the Fed will hold the line and remain very cautious about tapering asset purchases. We think it will keep communicating that tightening is very far off, which should dampen pro-dollar sentiment,” said UBS Global Wealth Management strategist Gaétan Peroux and analyst Tilmann Kolb. ING analysts said “the rise in rates will be self-regulating, meaning the dollar need not correct too much higher”. They see the greenback index trading down to the 90.10 to 91.05 range. The euro rose 0.4% to $1.2134. The single currency showed little reaction to purchasing manager index data, which showed a slowdown in business activity in February. However, factories had their busiest month in three years, buoying sentiment. The dollar bought 105.39 yen, down 0.3% and a continued retreat from the five-month high of 106.225 reached Wednesday.