(Sharecast News) - Kroger's stock fell sharply on Thursday after the American supermarket and multi-department store chain reported a mixed batch of fiscal first-quarter results.

The Cinicinnati-based retailer beat forecasts with a 2% increase in fiscal first-quarter sales to $46.12bn, ahead of the consensus forecast of $45.59bn, with identical sales - ex-fuel sales from stores that have been open for five full quarters - up 1.0% year-on-year.

However, adjusted earnings per share of $1.58 were up from $1.49 last year but missed analysts' estimates by a penny.

Gross margins fell to 22.7%, compared with 23.0% the year before, mainly due to the mix impact of higher fuel sales, higher transportation costs, egg deflation and planned price investments.

"We are pleased with our first quarter results, but we know there is more work to do," said chief executive Greg Foran.

The company reiterated its full-year guidance for identical sales growth of 1-2% excluding fuel, and EPS of $5.10-5.30.

Kroger's share price was down 6.1% at $58.07 by 1554 BST.