HALIFAX -- The latest passenger figures from the operator of the money-losing ferry that links Nova Scotia with Maine show a slight decrease when compared with last year, raising questions about the viability of the two-year-old service.

Nova Star Cruises issued a statement late Tuesday showing that over a three-month period, the number of passengers had declined six per cent to 37,800 by the end of August when compared with last year.

The company said the results were disappointing.

The biggest decline was in August of this year, when passenger numbers dropped by 22 per cent to 15,974.

As well, the number of Canadians travelling to Maine dropped by 40 per cent when compared to the three-month figures for last year.

The company blamed the weak Canadian dollar for the sharp fall.

The weak numbers come as the Nova Scotia government is rethinking its multimillion-dollar investment in the service, which started operating last year after a four-year hiatus.

The government has committed $13 million for the service for 2015, and in 2014 Nova Star received $28.5 million in subsidies.

Nova Scotia's Transportation minister, Geoff MacLellan, has said a decision on who will operate the Yarmouth to Portland ferry next year will be made after this sailing season is finished.

Three potential operators have expressed an interest in taking over the service.

Nova Star had asked for an additional $2.5 million this year, but MacLellan has said the company will not receive any more funding until the province has reviewed financial data it recently received. The province first started asking for Nova Star's 2014 audited financial statements more than four months ago and received them only last month.

The ferry service has set an overall goal of 80,000 passengers for this season, which began June 1. MacLellan has said 60,000 is more likely.

A spokesman for Nova Star did not respond to a request for comment.