Baxter International Inc. (BAX) posted a 12% gain in third-quarter profit that was helped by lower costs this year and a bigger tally of charges a year ago, although its sales were flat due to the effects of currency rates.

Excluding charges, profit in the recent quarter came in just ahead of Wall Street expectations, although sales were lighter than analysts expected, on average. The Deerfield, Ill., maker of treatments for serious problems such as hemophilia and kidney failure again boosted its full-year profit forecast, but included a fourth-quarter guidance range that still landed mostly short of Wall Street's expectations.

Shares of Baxter slipped in premarket trading Thursday and were recently down 3.5% to $54.98.

The company reported a third-quarter profit of $530 million, or 87 cents a share, up from $472 million, or 74 cents a share, a year earlier. Excluding costs in both quarters from product discontinuation and other items, earnings rose to 98 cents from 88 cents.

The adjusted tally came in ahead of Baxter's July forecast for third-quarter earnings of 95 cents to 97 cents per share, and was a penny above the average forecast among analysts surveyed by Thomson Reuters.

Sales of $3.15 billion were basically flat compared with the total a year ago, restrained by unfavorable currency conditions. Excluding the currency effect, Baxter said sales were up 6%.

Analysts, on average, had expected a higher sales total of $3.19 billion.

U.S. sales were up 5% while international sales fell 4% due to currency, but otherwise were up 7%.

Gross margin rose to 51.9% from 48.3% amid a lower cost of sales in the recent period.

Amid Baxter businesses, the bioscience business - the company's largest unit - posted a 2% rise in sales, or 8% excluding currency, helped by a treatment for hemophilia, antibody therapies and products derived from plasma.

Sales in the medication delivery business rose 1%, or 7% excluding currency. Sales in the renal business were down 3% due to currency, but increased 4% when this impact is excluded.

While currency has been a drag on Baxter sales so far this year, the sliding value of the U.S. dollar has altered conditions for big multinational companies, and Baxter forecast a currency-related sales benefit in the fourth quarter. It sees sales in the period up 8% to 10%.

It sees fourth quarter earnings of $1.02 to $1.04 per share, before any special items, which compares with Wall Street's $1.04 forecast.

For the full year, Baxter now sees potential for a slight sales gain due to the currency changes, although its sales-growth forecast excluding currency remains at 7% to 8%. It now sees earnings of $3.79 to $3.81 per share, which is up from the $3.76 to $3.80 per share forecast given in July.

-By Jon Kamp, Dow Jones Newswires; 617-654-6728; jon.kamp@dowjones.com

(Mike Barris contributed to this article.)