April 24 (Reuters) - Assa Abloy the world's

biggest lockmaker, reported a 5% increase in first-quarter

operating profit on Wednesday, citing strong operational

execution, continued strong price realisation and lower direct

material costs.

The Swedish company's quarterly operating profit, excluding

items affecting comparability, grew to 5.43 billion Swedish

crowns ($502 million) from 5.19 billion crowns a year earlier.

The rival to Allegion ( ALLE ) and Stanley Black & Decker ( SWK )

said its sales fell 2% organically in the first quarter.

"The organic sales were affected by three fewer working days

in March, the most important month of the quarter, and a

continued weak residential market," CEO Nico Delvaux said in a

statement.

On a reported basis, sales grew by 9% to 35.20 billion

crowns.

($1 = 10.8207 Swedish crowns)