Bristol-Myers quarterly sales meet Wall Street estimates

July 27 (Reuters) - Bristol-Myers Squibb Co posted a lower second-quarter net profit on Thursday as research and development costs increased, but sales of its key cancer immunotherapies continued to rise, meeting Wall Street estimates.

The company, which is facing pressure from activist investors after losing ground to rival Merck & Co's cancer treatment Keytruda, said sales of cancer drug Opdivo rose 42 percent from a year earlier to $1.2 billion, while sales of Yervoy rose 34 percent to $322 million.

Analysts, on average, had expected Opdivo sales of $1.1 billion and Yervoy sales of $307 million, according to Thomson Reuters I/B/E/S.

Sales of blood thinner Eliquis, another important Bristol-Myers drug, rose 51 percent from the year-earlier period.

Total revenue for the quarter rose 6 percent to $5.1 billion, meeting Wall Street estimates.

Excluding one-time items, Bristol's earnings of 74 cents a share matched the average analyst estimate.

The company raised the lower end of its 2017 adjusted earnings forecast to $2.90 from $2.85 a share, and left the top end unchanged at $3.

Bristol's net income for the quarter fell 21 percent to $916 million, while research and development costs rose 31 percent to $1.66 billion. (Reporting by Deena Beasley; Editing by James Dalgleish)