Canada is the world’s largest developed market oil producer and one of the largest non-OPEC producers, so it is not surprising that Canadian stocks are struggling as oil prices tumble.

That alone is problematic for U.S.-listed exchange traded funds, namely the iShares MSCI Canada ETF (NYSEArca: EWC), but talk that dividends at Canadian energy firms are vulnerable to cuts or suspensions could further pressure EWC and rival ETFs. [Cheap Oil Crimps Canada ETFs]

Earlier this week, Canadian Oil Sands said it will slash its quarterly dividend by 42%, report Jeremy van Loon and Rebecca Penty for Bloomberg, prompting speculation that if oil prices remain low, more Canadian energy producers could be forced to reduce or suspend payouts.

EWC, the largest Canada ETF trading in the U.S. with $2.86 billion in assets under management, features a 0.42% weight to Canadian Oil Sands. The ETF’s overall energy sector allocation is 22.7%, its second-largest sector weight behind a 39.2% allocation to financial services stocks.

As the United States Oil Fund (NYSEArca: USO) has tumbled 27.3% over the past 90 days, EWC has shed 10.4% over the same period. The Guggenheim Canadian Energy Income Fund (NYSEArca: ENY), which tracks Canadian oil and gas producers in the royalty trusts and oil sands resources categories, has plunged nearly 31%.

Last month, only four developed markets, including oil-heavy Norway and commodities-rich Australia, saw their equity markets perform worse than Canada, according to S&P Dow Jones Indices data. [Oil Crushed These Country ETFs in November]