BT and Yell were punished by investors today after the telecoms-based pair provided the City with cause for concern in third quarter results.

British directories firm Yell soothed the nerves of investors today as it continued its battle against “fierce” competition in the United States.

A warning about intense competition in the United States caused shares in directories group Yell to dive by as much as 17% today.

Directories group Yell today said online revenues in the UK jumped 71% during an “outstanding” quarter for its Yell.com business.

The owner of Yellow Pages, the UK version of the Golden Pages, bolstered it US operation today with a deal worth £829m (€1.2bn) for a leading directories publisher in California and Texas.