* Q1 adj EPS $0.80 vs est $0.73
* Q1 rev $271.5 mln vs est $237.8 mln
May 8 (Reuters) - Par Pharmaceutical Companies Inc, which is under pressure from an activist investor to consider selling itself, posted higher-than-expected results for the fourth straight quarter as most of its products sold well.
Ralph Whitworth's Relational Investors LLC raised its stake in the generic drugmaker and asked the company on Tuesday to focus its strategies on a potential takeover.
Par's first-quarter net loss from continuing operations was $28.7 million, or 79 cents per share, compared with $108.8 million, or $3.07 per share, last year.
Excluding a one-time charge, Par earned 80 cents per share.
Revenue rose 17 percent to $271.5 million.
Analysts on an average expected a profit of 73 cents per share, excluding items, on revenue of $237.8 million, according to Thomson Reuters I/B/E/S.
Shares in Woodcliff Lake, New Jersey-based Par Pharma closed at $42.16 on Monday on the Nasdaq.