HTC invited agencies to pitch for the UK work after elevating Nelson Bostock to a global brief two months ago.
Hope&Glory's work will be led by managing partners Jo Carr and James Gordon-MacIntosh, who will report to HTC's UK public relations manager Suzi Watson.
The brief includes handling HTC UK’s press office duties, helping manage the UK launch of new handsets, the reviews, product placement and lifestyle media programme.
Gordon-MacIntosh pointed to HTC’s strong reputation for its design, sound, cameras and software.
"There is a massive media opportunity to help to take that recognised foundation into wider lifestyle media," he said. "We’re looking forward to working together to develop some attention-grabbing activities that really bring the new 'change' promise to life for tech fans and wider consumers alike."
The agency steps in as HTC seeks to restore sales and its share of the market after a difficult 2012, in which the number of phones it sold dived by 26 per cent to 32 million globally.
As part of the fightback, it has launched a billion-dollar marketing campaign called ‘Here’s to Change’ and led by Hollywood star Robert Downey Jr.
However, this week the company was struck a blow after it emerged that Nokia is seeking an injunction to prevent the import and sale of the HTC One into the UK.
The legal attack on its flagship phone comes after Nokia won a patent dispute.
Dynamo’s work promoting the HTC One handset in the UK was unaffected by the review.