(Reuters) -Shell denied that it was in talks to buy BP after the Wall Street Journal reported on Wednesday that the oil major was in early discussions over a takeover of its British rival.

"No talks are taking place. As we have said many times before, we are sharply focused on capturing the value in Shell through continuing to focus on performance, discipline and simplification," a Shell spokesperson said.

A BP spokesperson declined to comment on the WSJ report.

The latest in a series of rebuttals by Shell follows recent repeated assertions by CEO Wael Sawan that Shell had a very high bar for big acquisitions and buying back shares was a better allocation of money than the possibility of buying BP.

BP has been the subject of takeover talks for several years because of its stock's relative underperformance, but analysis of its disclosures shows that the British energy group may not be as cheap as its market valuation would suggest.

The company was valued at nearly $80 billion on Wednesday with net debt of $27 billion while Shell's market capitalisation stood at more than $208 billion.

BP's American depository shares were up 1.5% at $30.40 by 1725 GMT and Shell was down 0.7% at $69.70.

If Shell were to submit a bid, it would be a rare attempt by an oil major to acquire such a large rival in the face of heightened regulatory scrutiny of such deals.

A deal of this magnitude has not been attempted in the energy industry since Exxon and Chevron held preliminary talks during the COVID-19 pandemic to discuss a combination that would have been the biggest merger of all time.

Potential terms of any deal could not be learned and a tie-up is far from certain, WSJ reported.

CNBC cited unidentified sources saying that BP could be broken up if a deal materialises.

BP's shares have fallen by 23% over the past year, underperforming the blue-chip FTSE 100 Index, which gained 5.3% during the same period. Shell's shares have risen more than 8% while Exxon has lost 4% with Chevron down about 10%.

(Reporting by Prerna Bedi and Aatrayee Chatterjee in Bengaluru and Shadia Nasralla in LondonEditing by Arun Koyyur, Jane Merriman and David Goodman)