LONDON (Reuters) - Average prices in British shops in August were 0.8% lower than a year before, a smaller decline than in previous months and one which reflected rising costs for stores, the British Retail Consortium said on Wednesday. The BRC’s measure of shop price inflation - unlike most other inflation measures - is typically negative. July’s reading showed a fall of 1.2% and the average annual decline over the past 12 months was 1.5%. “There are some modest indications that rising costs are starting to filter through into product prices,” BRC chief executive Helen Dickinson said. Price rises were most noticeable for electrical goods due to global shipping delays and a shortage of microchips, she said. Food prices were also likely to rise over the coming months due to rising commodity prices, increased transport costs reflecting a shortage of truck drivers, and greater post-Brexit costs for importing food from the European Union, she added. “Disruption has been limited so far, but in the run up to Christmas the situation could get worse, and customers may see reduced choice and increased prices for their favourite products and presents,” she said. Reporting by David Milliken, Editing by Paul Sandle Our Standards: The Thomson Reuters Trust Principles.