Canada\'s dollar had the biggest weekly gain in 20 months versus its US counterpart as rising optimism that European leaders have staved off a default by Greece fuelled investor appetite for higher-yielding assets. The loonie, as the Can-adian currency is nicknamed for the image of the aquatic bird on the C$1 coin, also strengthened as data showing inflation climbed more than forecast spurred bets the central bank will resume raising interest rates. The weekly gain reversed losses for the month and quarter. Canada\'s job growth slowed last month, a report this week may show. \"Risk appetite, that\'s the main driver of the Canadian dollar,\" said Shaun Osborne, chief foreign-exchange strategist at Toronto-Dominion Bank\'s TD Securities unit in Toronto. Article continues below \"One of the big uncertainties that has been hanging over the market lately has been a Greek default and a systemic problem in the global banking system and that seems to have been removed now.\" The Canadian currency strengthened 3.1 per cent to 95.85 cents per US dollar in Toronto on Friday, from 98.86 cents on June 24. It was the biggest gain since the 3.6 per cent advance for the five days ended October 9, 2009. The loonie touched 95.81 cents on Friday, the strongest level since May 11, after depreciating to 99.13 cents on June 27, the weakest in three months. One Canadian dollar buys $1.0433. The loonie gained 0.5 per cent for June and appreciated 0.8 per cent for the three months ended June 30, its fourth straight quarterly advance. Until last week it was headed for monthly and quarterly declines as crude oil, Canada\'s biggest export, dropped and stocks slid amid concern Greece\'s sovereign-debt crisis would worsen. The currency has risen 4.1 per cent in 2011, while being outperformed by 11 of its 16 most-traded peers. Commodities including oil had five-day gains for the first time in a month as Greek Prime Minister George Papandreou won lawmakers\' approval of an austerity plan needed to keep financial aid flowing to the debt-strapped nation and avert the euro region\'s first sovereign-debt default. Commodities, stocks Canada\'s dollar rose versus 15 of its 16 most-traded peers last week as crude gained 4.2 per cent to $94.94 a barrel in New York and the Thomson Reuters/Jefferies CRB Index of raw materials increased 2.1 per cent. Raw materials including oil account for about half of Canada\'s export revenue. The Standard & Poor\'s 500 Index of stocks climbed 5.6 per cent. The loonie jumped on Friday the most since December on an intraday basis after Statistics Canada reported the consumer price index increased at an annual pace of 3.7 per cent in May, the fastest since 2003, from 3.3 per cent the previous month. The currency climbed as much as 1.2 per cent as the data prompted traders to ratchet up bets the Bank of Canada will resume raising interest rates. The bank has held the benchmark overnight rate at 1 per cent since September after raising it three times last year. The yield on December 2011 bankers\' acceptances increased 14 basis points, the biggest weekly gain since February, to 1.5 per cent. It had touched 1.36 per cent last Sunday, the lowest closing since the contracts started trading in December 2008. The yield on so-called Baxes averages about 18 basis points above the central bank\'s overnight target, Bloomberg data since 1992 show. The CPI figure \"has us believe that we will be seeing a rate increase this calendar year,\" said C.J. Gavsie, managing director for foreign-exchange trading at Bank of Montreal\'s BMO Capital Markets unit in Toronto.