Investing.com -- A group of U.S. investment firms led by KKR and Energy Capital Partners is in advanced discussions to buy Ireland's DCC, with a revised offer valuing the energy distributor at more than £5 billion ($6.69 billion), Sky News reported on Wednesday.

DCC rejected the consortium's initial proposal in late April, which offered £58 per share or £4.95 billion. The company said the bid undervalued its business.

The new offer values DCC at approximately £65 per share, a 12% increase from the earlier rejected bid, according to Sky News.

Shares of the London-listed company rose 2.8% to £61.75 on Wednesday. The stock has gained about 11.5% since the April offer, based on Tuesday's close.

The consortium must submit a firm offer or withdraw its bid by 5:00 pm GMT on Wednesday under UK takeover rules. If the group walks away, it cannot pursue DCC again for six months.