The romance publisher has called the range '12 Shades of Surrender' and given the titles covers that evoke EL James's bestselling trilogy.
"Mills & Boon has published erotica under the Spice imprint since 2008," head of marketing Tara Benson is quoted as saying by The Bookseller.
"These 12 titles are a selection of the best editorial from our finest writers, re-jacketed to speak to fans of Fifty Shades who are looking for their next erotic read."
Head of digital Tim Cooper added: "We have experienced a boom in our whole range of romantic fiction as well as our erotica line over recent years.
"It is great to offer female readers the full range of content from soft romance through to erotica, so they can choose the right book for their mood. Since launch our monthly sales of Spice have grown 1,150%.
"Erotica is becoming more mainstream and acceptable as we and others evolve our packaging to become less explicit and women become ever more empowered to read what they want to and enjoy."
Books in the £1.99 range include Cuffing Kate by Alison Tyler, Going Down by Saskia Walker and Taking Her Boss by Alegra Verde.
Fifty Shades of Grey became the fastest-selling adult paperback to reach one million copies last month, after previously topping a million eBook sales on Amazon UK's Kindle Store.