Morrisons, the UK's fourth-largest grocer, is to test new management structures in seven stores it plans to open later this year.

The retailer said it would use the new stores to trial changes it hoped would "simplify" management structures and improve customer service.

Morrisons, which is working to improve its performance after successive quarters of falling sales, insisted the move was not aimed at cutting jobs.

"We can be absolutely clear that the trials are not about reducing the numbers of staff in stores," a spokesperson said.

In May, Morrisons revealed like-for-like sales, excluding fuel, had fallen in the first quarter of its new financial year. The result followed a year in which LFLs dropped 2.1%, excluding fuel.

To stem the fall in sales and arrest declining market share, Morrisons introduced a new advertising campaign - with the tagline "more of what matters" - and rolled out a new loyalty scheme - called "payday bonus".

In a note issued on Friday, Shore Capital retail analyst Clive Black said Morrisons' "under-performance" was "improving".

"Whilst Morrisons is still losing market share, it is no longer reporting falling sales, as it was in calendar Q1 2013, and the differential in under-performance has narrowed markedly; indeed the most recent market share data has reported Morrisons performing broadly in-line with Asda and Tesco," Black wrote.

Morrisons last week closed its deal with Ocado that will see it launch an online grocery service early next year in a venture with the digital specialist. It is set to report its half-year results in September.