For months, speculation has been building that the London energy giant BP could be acquired by a competitor. Its lackluster returns and low share price have made it a tempting takeover target.

An activist shareholder had built up a significant stake in BP and was pushing the company to sell assets to raise cash, and industry analysts began to wonder how long it would take until the entire company was on the auction block.

The situation came to a head on Thursday when Shell, BP’s crosstown rival, was forced to issue a denial to media reports about merger talks between the two companies.

BP, which remains one of the world’s largest energy companies, is beginning to take steps to enhance its appeal to investors, including cutting costs and bolstering the oil and gas operations that produce the cash to fund the company’s large dividend payouts.

It may struggle, though, to shake off the impression that it is a troubled company in danger of losing control of its own destiny.

“We don’t expect that the statement today will stop this,” Ashley Kelty, an analyst at Panmure Liberum, a financial firm in London, wrote in a note to clients on Thursday, referring to Shell’s denial that it had approached BP for a possible takeover.