(Reuters) – The takeover battle for drugmaker Vectura will enter an auction process if Carlyle Group and Philip Morris do not make final bids by Tuesday, according to British regulators.

“The auction procedure provides for up to five days of public bidding from Aug. 10,” UK’s Takeover Panel said in a statement on Monday.

Vectura, which makes respiratory treatments, separately said it was withdrawing its recommendation for Carlyle’s increased offer of 155 pence per share and that it had no intention yet to recommend Philip Morris’ 165 pence proposal from Sunday.

The drugmaker on Friday voiced concerns around Philip Morris’ ownership, saying it might be better positioned under Carlyle and backed the private equity group’s latest offer.

Vectura makes inhaled medicines and devices to treat respiratory illnesses such as asthma, and counts Novartis and GSK among its customers. It has also agreed to develop a potential inhaled treatment for COVID-19 with Inspira.

(Reporting by Pushkala Aripaka in Bengaluru; Editing by Subhranshu Sahu and Ramakrishnan M.)