U.K. smart meter firm Calisen Group Holdings has called on Simpson Thacher & Bartlett to advise on its anticipated float on the London Stock Exchange, in what is expected to be London's first initial public offering (IPO) this year.

The Manchester-based company is owned by private equity firm KKR and is the leading owner and manager of essential energy infrastructure assets. Calisen's operations consist of two business units, Calvin Capital and Lowri Beck.

According to a statement announcing its intention to float, Calisen says it expects to raise around £300 million, alongside an offer of existing shares to be sold by certain existing shareholders.

Calisen's CEO Bert Pijls described the announcement as an "incredibly exciting moment in the history of Calisen, providing us with the platform for our next phase of growth in an expanding segment, and positioning us as a leading provider of essential energy infrastructure in Britain".

Recent IPOs Simpson Thacher has acted on includes Chinese technology giant Alibaba Group Holding Ltd.'s $13 billion Hong Kong listing.