By Saumya Joseph

(Reuters) - Johnson & Johnson <JNJ.N> raised its full-year earnings forecast on Tuesday as it reported higher third-quarter sales of psoriasis treatment Stelara and cancer drug Imbruvica while attempting to alleviate investor concerns over mounting legal challenges.

Shares of the U.S. healthcare conglomerate, which also has huge medical devices and consumer products units, rose 2% to $133.70, contributing to a strong early performance on Wall Street overall on Tuesday.

J&J shares have been under pressure this year, widely underperforming the S&P healthcare sector <.SPXHC>, as the company faces more than 13,000 lawsuits tied to antipsychotic drug Risperdal as well as a range of potentially costly lawsuits involving its baby powder, opioids, medical devices and other products.

J&J did not report litigation expenses for the third quarter. Its legal costs over the first nine months remained at $832 million, as was reported at the end of the second quarter. It did not respond to a Reuters request for additional details on legal costs.

The company is the first major drugmaker to report quarterly earnings and its upbeat outlook and results could be a positive sign for the sector.

SVB Leerink analyst Danielle Antalffy said the quarterly results should be viewed positively by investors, but cautioned that the ongoing litigation overhang could limit any boost share boost.

The company reiterated that it does not expect last week's outsized jury award of $8 billion in punitive damages J&J was ordered to pay a man in a Risperdal product liability case to stand.

"We will appeal the amount and you can expect that to come down should precedent hold," said Chief Financial Officer Joseph Wolk on a conference call.

Bernstein analyst Lee Hambright was encouraged by J&J reassurances on its legal strategy. "I think they are fighting from a position of strength on talc and on opioids."

"They both emphasized on the strength of their case but also projected a sense of pragmatism to settle where it's the right thing to do for all stakeholders," Hambright added.

J&J's pharmaceuticals business has in recent years cushioned the impact of relatively slow growth in its medical device and consumer units. Much of the growth has come from newer treatments such as Stelara, which reported near 30% growth in sales to about $1.7 billion. Sales leukemia treatment Imbruvica rose about 31% to $921 million in the quarter.

The company said it now expects full-year adjusted earnings per share in the range $8.62 to $8.67, up from its prior forecast of $8.53 to $8.63. Analysts were expecting $8.60 per share.