US drugs giant Pfizer is poised to kick off the long awaited sale of its $3.4 billion consumer health unit next month, news agencies speculate.

According a calculation by Reuters, the unit could fetch as much as $15 billion, and a deal could be concluded by the middle of 2018. One of its sources said Pfizer believes keen competition would allow it to raise at least $20 billion from the sale of the business that includes products ranging from branded to multivitamins and lip balm.

The prospective sale is being led by Centerview Partners, Guggenheim Securities and Morgan Stanley.

Among candidates to take over the business, GlaxoSmithKline (GSK) and Reckitt Benckiser have already been identified. Other mooted bidders are could Procter & Gamble, Sanofi, Johnson & Johnson and Nestle, reports said.

During a press conference to present financial results, GSK’s new CEO, Emma Walmsley, confirmed that the UK firm could be interested.

Reuters added that US drugmaker Merck would like to put its consumer health business, (worth around $4.5 billion) on the sale block but fears the Pfizer auction could suck up too much deal-making oxygen.

Pfizer said earlier in October it was exploring a sale or spinoff of the business.