Hart, who has more than 13 years' experience in direct marketing, has already set up a business that exports to Europe, IT asset management specialist Europlus Direct.
TEMA's services range from direct marketing to multilingual website design and inbound call handling.
Hart, who is managing director, has brought in Carl Hopkins, the former chairman of direct agency JDA, as a consultant with a view to becoming a non-executive director later this year.
Patrick Kavanagh, the account director, has worked in experiential marketing for clients including Coca-Cola, Unilever and Campbells.
Hart said: "With TEMA, we hope to take away the pain of exporting and marketing into mainland Europe and help unravel the complexities of language, culture and law often faced by UK businesses when looking to expand.
"Whether it's developing an e-marketing campaign that adheres to Spanish regulations or sourcing pan-European databases, we have the knowledge and expertise to help companies expand on a global scale."
Launch clients include European holiday specialist Siblu and Salts Custom Tailors.