Bloomsbury Publishing yesterday showed that there was more to its business than its Harry Potter books, with an acquisition to boost its reference list.

The company bought Peter Collin Publishing, a producer of dictionaries, for £860,000. Peter Collin, a private company founded in 1985, puts out a range of specialist and bilingual dictionaries, including the UK's best-selling crossword reference title, Bradford's Crossword Dictionary. It publishes more than 130 subject dictionaries and language titles that are used by students, translators and professionals.

The business is not related to the Collins family of dictionaries that are published by New Corporation's Harper Collins division.

Bloomsbury's chief executive, Nigel Newton, commented: "This acquisition extends the range of our reference content and demonstrates Bloomsbury's commitment to growing its sources of high-quality repeat revenues."

In 2000, Bloomsbury bought the reference publisher A&C Black, the company behind Who's Who, for £16m. Bloomsbury publishes the EnCarta dictionaries and recently bought Whitaker's Almanack. Since 1996 Bloomsbury Reference has created more than 25 million words of dictionary and reference content.

Bloombury will report interim results today and later this week it will release its latest reference work, Business: The Ultimate Resource, which is billed as a "one-stop reference source for everyone at work".

Mr Newton said: "The acquisition will help us achieve our aim of increasing our presence in the reference markets both in the UK and in the US."