April 22 (Reuters) - Toronto-based semiconductor group Alphawave said on Thursday it was planning to apply for a London listing of its shares, adding that the cornerstone agreement with certain investors gave it a valuation of up to $4.5 billion. The initial public offering would include issuing new shares, raising roughly $500 million, as well as an offer of existing stock to be sold by current shareholders, the company added. Alphawave, founded in 2017 and profitable since 2018, said funds and accounts managed by BlackRock and Janus Henderson have entered agreements with it to subscribe for $510 million of offer shares at a price that gave it an equity value of up to $4.5 billion at admission. “We have chosen to come to the UK because of its incredible technology and semiconductor industry ecosystem. The strong research base in the UK - and our new R&D headquarters in Cambridge - offers an excellent foundation for the next stage of our global growth,” Chief Executive Tony Pialis said. (Reporting by Muvija M in Bengaluru Editing by Rachel Armstrong)