MONTREAL - Valeant Pharmaceuticals says it expects to produce less revenue in the first quarter of 2016 than previously thought and it had a net loss of US$336.4 million in the final quarter of 2015 - rather than a profit as analysts expected.

The loss - reported in U.S. currency - was largely due to costs associated with restructuring and acquisitions.

After adjustments, Valeant says it earned US$875.7 million, or $2.50 per share, from just under $2.8 billion of revenue.

Analysts had estimated a net profit of US$462.6 million and higher adjusted earnings of US$942.8 million, or $2.61 per share, according to Thomson Reuters.

Valeant didn't report comparisons with year-earlier results because of a previously announced restatement of its previous financial reports, due to errors in the way Valeant recognized revenue from Philidor Rx Services in 2014 and 2015.

However, it reduced its previous sales and adjusted earnings estimates for the first quarter of 2016.

Valeant now estimates between $2.3 billion and $2.4 billion in revenue, down from the previous estimate of between $2.8 billion and $3.1 billion.

Adjusted earnings are estimated at between $1.30 and $1.55 per share, down from between $2.35 and $2.55 per share.

The results issued Tuesday were delayed by the recent return of Valeant chief executive Michael Pearson after a two-month medical leave that began just before Christmas as the was grappling with numerous issues.

The Quebec-based company has struggled since a critical report disclosed connections with Philidor, a U.S. mail order pharmacy, amid political accusations of price gouging that further punished its reputation.

Once one of Canada's most valuable companies, Valeant has seen its stock price and market capitalization cut by more than half since October.

Valeant's net profit is expected to fall 15 per cent to US$462.6 million despite a 20 per cent increase in revenues, according to analysts polled by Thomson Reuters.

However, adjusted profits, which exclude one-time charges, are forecast to rise to US$942.8 million, or $2.61 per share, from $880.7 million, or $2.58 per share, a year earlier.

That's within the range of the company's revised forecast issued in mid-December.

The company has said it would delay filing its 2015 annual report with regulators while it continues to sort out the impact of its former relationship with Philidor Rx Services. Valeant said the source of the problem for its results involves US$58 million of sales to U.S. mail-order pharmacy Philidor that were recognized at the wrong time.

It estimated the company's 2014 earnings will be reduced by 10 cents per share, in U.S. currency, and 2015 earnings will be increased by nine cents per share

After ending ties in October with Philidor, Valeant launched a new distribution deal with Walgreens, a prominent U.S. drugstore chain.

The Laval, Que.,-based company has confirmed it is being investigated by the U.S. Securities and Exchange Commission. It is also under investigation by U.S. Attorney's offices in Massachusetts and New York, as well as Congress, as part of their probes into big price increases for certain specialty drugs.