(Adds oil price and revenue forecasts)
Nov 30 (Reuters) - The Alberta government on Friday trimmed its 2018-2019 budget deficit estimate, but downgraded the 2019 economic growth forecast in the Canadian province due to faltering crude oil prices.
The deficit looks to reach C$7.5 billion ($5.7 billion), compared with C$7.8 billion projected in August, the government said in a statement.
The left-leaning New Democrat government led by Premier Rachel Notley had budgeted in April for an C$8.8 billion deficit. She faces a provincial election in spring.
Low Canadian oil prices compared to the U.S. West Texas Intermediate benchmark (WTI) reflect full pipelines that have stranded crude supplies in Alberta, away from the U.S. refineries that buy the oil.
"This is a crisis," Finance Minister Joe Ceci said in a statement, referring to the price discount known as the differential. "If the differential is not addressed, our entire country could be plunged into a downturn."
The province downgraded its forecast for 2019 economic growth to 2 percent from a budgeted 2.5 percent, due to oil production curtailments amounting to 150,000 barrels per day and expected weaker corporate profits.
It continues to forecast a return to fiscal balance in 2023-24.
Discounts on Canadian crude hit record highs in October, compared with WTI prices. WTI has tumbled sharply since October.
Even so, Alberta expects non-renewable resource revenue, mainly from oil and gas, to rise in 2018-19 to C$5.3 billion, exceeding the C$3.8 billion that it had budgeted. The higher revenue estimate reflects more favorable oil prices between spring, when the budget was set, and autumn, government officials said.
The government assumes an average discount of $29.25 per barrel for Canadian heavy crude in 2018-19, against an expected WTI price averaging $64 a barrel.
Alberta is the No. 1 crude exporter to the United States.
Low oil prices are so damaging to Alberta's economy that the provincial government plans to buy trains to transport an additional 120,000 barrels per day of crude, hoping to improve prices by smoothing transport to buyers.
It is also considering calls from some oil producers, including Cenovus Energy and Canadian Natural Resources , to impose mandatory oil production cuts on producers.
Alberta expects to spend C$56.6 billion in 2018-19 and collect C$49.6 billion in revenue.
The budget includes a C$500 million cushion for risk.
The 2018-19 fiscal year ends on March 31.
($1 = 1.3281 Canadian dollars) (Reporting by Rod Nickel in Winnipeg, Manitoba; Editing by Richard Chang and Tom Brown)