(Adds details, shares)
June 26 (Reuters) - Penn Virginia Corp shareholderLone Star Value Management LLC asked the U.S. oil and gasproducer to consider strategic alternatives to explore "allcredible proposals".
Lone Star's statement on Friday comes a day after financialnews website Proactive Investors reported that BP Plc hadoffered to buy company for $8 per share.
"If it is true that Penn Virginia could be sold for an 80percent premium or more to a credible buyer, the board has afiduciary duty to fully explore such an offer," said Lone Star,which has a 2.8 percent stake in Penn Virginia.
Penn Virginia shares closed up 12 percent at $4.98 onThursday after news of BP's offer was reported, valuing thecompany at $356.9 million.
Lone Star said Penn Virginia was an attractive takeovertarget because of its acreage in Texas' Eagle Ford shale.
The company had proved reserves of about 115 million barrelsof oil equivalent as of Dec. 31 and produced 24,721 barrels ofoil equivalent per day in the January-March quarter.
If Penn Virginia rejects an offer with a substantialpremium, Lone Star said it may seek shareholder representationon the board.
Penn Virginia declined to comment.
Lone Star said on Friday Penn Virginia shares had"significant upside potential" in the event of an oil pricerecovery, but criticized the company for its "history of poorperformance, its stale board, and its high cost of capital." (Reporting by Amrutha Gayathri in Bengaluru; Editing by SavioD'Souza)