TORONTO (Reuters) — Canada's main stock index slipped on Tuesday as a slump in shares of Potash Corp following disappointing results from rival fertiliser company Mosaic Co offset gains in gold-mining stocks.The Toronto Stock Exchange's S&P/TSX composite index. GSPTSE unofficially closed down 11.46 points, or 0.09 percent, at 12,516.89. Nine of the 10 main sectors on the index were in the red.Shares of Canadian patent licensing company WiLan Inc soared on Tuesday, shrugging off a court ruling that four of its patents had not been infringed.In other headlines, WiLan's NASDAQ-listed shares fell as much as 33 percent after the bell on Monday on the news but surged 15 percent on Tuesday. Its Toronto-listed shares rose 19 percent to C$3.91.Some analysts said the company, whose principal source of revenue is from licensing its patent and licensing portfolios on behalf of third-party patent holders, lost a battle, not the war, while others termed the judgment ‘a bump in the road’."It was a negative announcement, but I think I would frame it as one step in a longer process as opposed to the very negative reaction that the markets had gone into yesterday," Canaccord Genuity analyst Robert Young said.Stifel Nicolaus analyst Blair Abernethy said the company has multiple relevant patents in its portfolio of over 3,000 patents and it could initiate further lawsuits to secure licenses."There is a high likelihood that WiLAN will appeal this verdict," said Abernethy, who maintained a ‘buy’ rating on the stock, but cut the price target to C$5.50 from C$6.Canadian factory sales in May rose by 0.7 percent from April, making up some of the ground they lost during a plunge the previous month, Statistics Canada said on Tuesday.The advance — just the second in five months — matched analysts' predictions. StatsCan revised April's initial 2.4 percent drop to 2.1 percent, which represents the worst month-on-month decline since August 2009.Also in Canadian business news, sales increased in 11 of 21 industries, representing about 57 percent of the manufacturing sector. Constant dollar sales rose by 0.7 percent on higher volumes.The chemical industry posted the biggest sales gain in dollar terms on an unusually large increase in fertiliser sales.Wetter and colder weather delayed spring planting this year, which meant the annual increase in fertiliser production occurred later than usual, StatsCan said.Inventories edged down by 0.2 percent, the first decline after four months of gains, while the inventory-to-sales ratio slipped to 1.42 in May from 1.43 in April. The values for the ratio in April and May were the highest since late 2009.