(Adds forecasts, analyst comment, Q2 earnings, background, company comment)

By Bill Berkrot

July 14 (Reuters) - Celgene Corp said on Tuesday it would buy Receptos Inc for $7.2 billion in a move that will give the U.S. biotechnology company a potential multibillion-dollar drug in late stage development for inflammatory bowel disease and multiple sclerosis.

Celgene, whose shares rose nearly 6 percent in extended trading to $130.15, said it would pay $232 per share in cash for the smaller biotech. Receptos shares closed at $207.18 on Nasdaq and rose to $228.14 after hours.

Celgene has been on something of a deal spree in recent months. The Receptos move comes just two weeks after Celgene said it would invest $1 billion in Juno Therapeutics to gain access to its cancer immunotherapy portfolio in a deal that would allow Celgene to buy up to 30 percent of Juno over the next decade.

The company also has collaborations with Agios Pharmaceuticals, which has a very promising leukemia drug in development as well as other oncology prospects, and with AstraZeneca in immuno-oncology.

"We have been fortunate to have been able to act on several major transactions that position us for sustained and enhanced long-term growth," Celgene Chief Executive Bob Hugin said on a conference call.

"The Receptos acquisition provides a transformational opportunity for Celgene to impact multiple therapeutic areas," Hugin said.

The deal should give Celgene lucrative new revenue sources, accelerating earning growth beginning in 2019, Hugin said, adding that "it will be a key driver of growth well beyond 2020."

The acquisition is expected to cut into Celgene earnings in 2016 and 2017 and be neutral in 2018, the company said.

"They found a very largely derisked late stage asset that can really move the needle," said Cowen and Co analyst Eric Schmidt. "And they didn't seemingly overpay, so it's a pretty good deal."

Receptos in April reported positive data in ulcerative colitis from a midstage trial of its experimental oral drug ozanimod, the medicine at the heart of the Celgene deal.

Phase III ozanimod trials are underway for both ulcerative colitis and relapsing MS. The drug could be approved for MS in 2018, Celgene said, putting the company into a new therapeutic area. Phase III colitis data are expected in 2018.

Celgene forecast peak annual ozanimod sales of $4 billion to $6 billion for UC and MS.

The drug also has potential use in Crohn's disease, psoriasis and atopic dermatitis, Celgene said. Those are all conditions with very large patient populations.

Given its confidence in ozanimod, Celgene raised its 2020 financial targets. It now expects product sales to exceed $21 billion and adjusted earnings to exceed $13 per share, up from prior 2020 forecasts of sales greater than $20 billion and earnings of $12.50 per share.

Celgene also reported preliminary second quarter results and updated its full-year forecast.

It now expects 2015 adjusted earnings of $4.75 to $4.85 per share, up from its previous range of $4.60 to $4.75. It still sees 2015 product sales of $9 billion to $9.5 billion.

For the second quarter, Celgene reported revenue of $2.28 billion, up 22 percent from the year-ago quarter.

It said it expected to report net earnings of 43 cents per share, down from 72 cents a year ago, due to expenses for collaboration payments. It said adjusted earnings would be about $1.23 per share, up from 90 cents a year ago and above Wall Street expectations of $1.14.

J.P. Morgan and Citi are acting as financial advisors to Celgene on the Receptos transaction. Centerview Partners LLC is acting as financial advisor to Receptos. Legal counsel for Celgene is Proskauer Rose LLP, and Receptos' legal counsel is Latham & Watkins LLP.

(Reporting by Bill Berkrot in New York; editing by Cynthia Osterman)