Japan's largest egg distributor, Zen-Noh Tamago Co., will raise wholesale prices of eggs to supermarkets and other mass retailers on 1 August, according to Japan's Corporate News Network.

Egg prices have remained stable for years but they are being raised to reflect higher production costs resulting from the boom in feed grain prices.

The price hike will cover high value-added products for which wholesale prices are fixed for a certain period. The Tokyo-based company will raise prices by about ¥30 per pack of 10 eggs.

If the full wholesale price increase is passed on, the retail price of the company's high-quality egg brand 'Shintamago' - currently set at around ¥300 per pack - will be raised by some 10 per cent.