Gloss Media, which will launch officially in June, will be run by managing director Yvette Colegrave out of one suite in the Carlisle Street building.
The company will produce digital and online focused idents and commercials which, it is hoped, will complement Unit's VFX arm.
Unit Post managing director David Peto said: “We're looking to Gloss's expertise so that we can crew up to do VFX shoots - particularly green-screen. This will allow us to take creative control of the whole special effects process for clients.”
Colegrave had been a freelance commercials producer for web specialist Guerilla. The company went into administration in January but was relaunched as Big Kid London, under parent company Fresh Media Group. The new incarnation's focus is largely corporate and this led to Colgrave's departure, taking a number of commercials clients with her.
Colegrave said of the new agreement: “This partnership with Unit has been very promising so far - we can offer clients a one-stop shop which provides very competitive rates.”
Gloss will look to work on high-end branding and commercials and it has already completed a series of sponsorship idents for Blue Square.
Members of the Unit VFX team, including Melanie Woodridge who comes from MPC, were also involved in that project.
Colegrave has also secured a deal to produce commercials showreels for six directors including Mike Valentine and Rob Caplin.