(Sharecast News) - Shares in oil and gas investment firm Upland Resources tanked on Monday after it said that a potential takeover bid had turned out not to be "bona fide".

Upland shares surged last week after it said it had received and rejected an unsolicited, "very preliminary" approach about a possible takeover offer at 14p a share from SEC Capital.

Under takeover rules, SEC had until 20 November to announce a firm intention to make an offer or walk away.

But on Monday, Upland said that once the offer period began, SEC "became unengaged and failed to sustain communications" with it.

"Further investigation and evidence eventually led to the conclusion that the 'potential offeror' was not bona fide," it said, adding that this was confirmed by the Takeover Panel.

Upland said it now considers the matter closed and is focused on executing its defined strategy of exploring, appraising and developing Block SK334 in Sarawak.

Chief executive Bolhassan Di said: "The company's full focus is on the SK334 PSC and developing the asset. The Upland team have spent many years working to progress block SK334 in Sarawak and to countenance any premature, preliminary offers is not part of this particular company's strategy.

"Upland Resources as an entity is fully committed to unlocking the full value potential of something we consider to be unique amongst the world's remaining high potential lower risk oil and gas exploration plays."

At 1242 GMT, the shares were down 41% at 2.66p.