Encyclopaedia Britannica Inc., the education technology company and publisher of books including the Merriam-Webster dictionary, is seeking a valuation of about $1 billion its initial public offering, according to people with knowledge of the matter.The Chicago-based company known for its historic namesake encyclopedia is working with advisers and may launch the offering as soon as June, the people said. Britannica announced in January it had filed confidentially for an IPO, according to a press...