Waitrose and Boots are considering trialling several different store formats simultaneously as they thrash out details of their forthcoming tie-up, The Grocer has learnt.

A source familiar with the negotiations said the two may launch Waitrose c-stores in some Boots, with a limited Waitrose range in other stores, as well as other options in between, before they decide how to progress.

The two retailers are understood to have seconded a small team of senior commercial staff to work full time on the specifics of the deal, announced in September. At the time, Waitrose said it also had ambitions to open 300 c-stores within 10 years.

"What you might see is Waitrose using Boots to open a large number of c-stores," said a source. "Boots stores offer the opportunity for a few hundred c-stores selling a complete range of Waitrose c-store food, not just lunch-time products."

In September, Waitrose said the trial, rumoured to involve about 50 branches, would start "early next year" but it is understood it won't begin until spring, while the retailers develop their supply chains.

"I don't expect anything to materialise for months," the source added. "The biggest issue they have is logistics. Whatever they might like to trial, how they do it is quite complicated. There are an awful lot of issues."

Waitrose MD Mark Price recently revealed a review of Waitrose's business structure was under way. "We've needed to look at the way the whole business functions as we've grown quickly with new formats and franchising," he said.

Waitrose has introduced service station branches, foodhalls in two John Lewis stores and two international stores in Dubai. The Boots tie-up is potentially the most ambitious because of its 2,600 stores, 700 of which sell food.

Under the deal, Waitrose will rebrand 17 of its in-store pharmacies as Boots and stock some Boots-brand products in-store as part of efforts to improve health & beauty sales.