Last month, Channel 6 submitted an expression of interest to Hunt about running the new national channel on Freeview, providing a "backbone" for local services around the UK.
STV, the holder of the ITV licences for STV and Grampian, has teamed up with Channel 6 to boost its own local media operation in Scotland, including the STV Local network of hyper-local websites.
Horwood, a former Trinity Mirror executive, said that STV is "trusted" across Scotland as a provider of news and programming with a local focus.
"STV has pioneered local services with the rollout of its hyper-local internet sites, which currently cover one third of Scotland and will eventually cover the whole of the nation," said Horwood.
"Our partnership with STV will enable us to deliver a truly relevant service right across Scotland, and will define the template for our local services in the other devolved nations."
He added: "STV is the one UK network broadcaster that has shown real ambition in local programming. We are delighted that they have chosen to work with us as our first major broadcast partner.
"Both Channel 6 and STV share Jeremy Hunt's belief that the time has come for the United Kingdom to experience the transforming power of local television, and we look forward together to helping the Secretary of State fulfil his vision."
Rob Woodward, the chief executive of STV, said: "STV is delighted to be working with Channel 6 as its partner supporting its vision to make local television a reality.
"In Scotland our 'STV Local' initiative already provides unique content for communities across the country. Our television heritage and local resources mean we are ideally placed to deliver expertise to support Channel 6 and targeted, local TV programming to Scottish viewers as part of the Channel 6 offer."
In total, 11 bidders are known to have submitted local TV proposals to Hunt's Department for Culture, Media and Sport before the deadline expired on March 1.
Confirmed bidders include Element TV and a Scottish consortium, along with former ITV News editor Nigel Dacre and Welsh independent production company Tinopolis. Also in the running is the Local Television Network, led by Greg Dyke, the Local6 group, backed by former Channel 4 chairman Luke Johnson and TripleSee, an IPTV joint venture fronted by former BBC executive Simon Walker.
Another bidder to emerge is local media operator Six Television, which is backed by UKRD, owner of 16 local commercial stations including Cornwall's Pirate FM and Spire Radio in Salisbury.
The successful bidder will receive the hugely valuable sixth slot on digital terrestrial television (Freeview) electronic programme guides from 2013.