Canadian stocks were lower Friday as rising tensions in Ukraine made for nervous investors going into the weekend.The S&P/TSX composite index declined 30.85 points to 14,523.4 amid another slate of corporate earnings. The Canadian dollar was up 0.01 of a cent to 90.69 cents US.U.S. indexes also retreated with the Dow Jones industrials down 99.34 points to 16,402.31, the Nasdaq dropped 40.33 points to 4,108.01 and the S&P 500 index slid 8.42 points to 1,870.19.There were scattered reports of violence Friday as Ukrainian forces try to end an occupation of government buildings by pro-Russian militia in more than 10 cities in eastern parts of the country. In turn, Russia’s foreign minister has accused the West of plotting to control Ukraine and also announced military exercises near Ukraine’s border.At the same time, the economic cost to Russia for its stance toward Ukraine increased as Standard & Poor’s cut Russia’s credit rating to BBB-minus — one step above speculative or non-investment grade. The previous rating was BBB.S&P said it took the step because the tense situation “could see additional significant outflows of both domestic and foreign capital from the Russian economy.”The latest round of tensions came at the end of a generally positive week thanks to a series of better than expected corporate earnings in Canada and the U.S.On Friday, automaker Ford said first-quarter net income fell 39 per cent to US$989 million, or 24 cents per share, down from $1.64 billion, or 41 cents per share, a year ago and seven cents below estimates. Revenue rose slightly to $35.9 billion, beating analysts’ expectations for $34.2 billion and its shares fell 3.25 per cent to $15.79.After the close Thursday, Microsoft reported quarterly earnings per share of 68 cents, five cents better than estimates. Revenue of $20.4 billion narrowly beat expectations of $20.39 billion and its shares rose 1.15 per cent to $40.32.In Canada, business software provider Open Text Corp. (TSX:OTC) posted quarterly net earnings of $45.8 million or 33 cents per share, up from $25.8 million or 22 cents in the comparable year-earlier period as revenue rose to $442.8 million from $337.7 million. The company also upped its quarterly dividend by 15 per cent to 17.25 cents a share. Its shares climbed $2.69 to $53.50.In other corporate developments, Canadian Oil Sands Ltd. (TSX:COS) lowered its production guidance for the Syncrude Canada oilsands mine north of Fort McMurray, Alta., as a result of a breakdown at one of its cokers, which help convert heavy oilsands bitumen into a lighter type of crude. COS cut its production estimate for 2014 to between 95 million and 105 million barrels, compared with an previous estimate of 95 million to 110 million barrels. Its shares fell $1.11 to $23.02.The energy sector led decliners, down 0.66 per cent while June crude in New York gave back $1.27 to US$100.67.The gold sector was the leading advancer, up 1.2 per cent as geopolitical worries drove June bullion up $10.80 to US$1,301.40 an ounce.May copper was unchanged at US$3.12 a pound and the base metals group was ahead 0.55 per cent.