June 25 (Reuters) - Penn Virginia Corp's shares roseas much as 15.5 percent on Thursday following a report that BPPlc had offered to buy the U.S. oil and gas producer for$8 per share.
The offer, which values the company at about $573 million,represents an 80 percent premium to Penn Virginia's Wednesdayclose of $4.45. The company's shares were trading at $5 onThursday afternoon.
Penn Virginia has rejected the offer saying it undervaluesthe company, financial news website Proactive Investorsreported, citing sources familiar with the situation. (http://bit.ly/1eJjp4g)
BP declined to comment, while Penn Virginia was notimmediately available for comment. (Reporting by Anannya Pramanick in Bengaluru; Editing bySaumyadeb Chakrabarty)