(Reuters) - OneSavings Bank (>> OneSavings Bank PLC) raised its loan book growth expectations for the full year as it focussed on bigger, professional landlords, even as the broader market lost its sheen for amateur landlords due to tax and regulatory changes.

The company said it now expects loan book growth of about 20 percent for the full year, from its previous growth expectation in the high teens.

The group grew its loan book by 16 percent to 5.9 billion pounds in 2016.

Kent-based OneSavings said it had increased its market share, helped by its focus on professional landlords.

OneSavings, one of the banks aiming to challenge Britain's so-called Big Five lenders, said last year that it had increased its focus on professional landlords and tightened lending criteria for financing smaller developments after Britain's vote to leave the European Union.

Historically, 90 percent of Britain's buy-to-let market has been in the hands of amateur investors, but a string of tax and regulatory changes announced last year have made the sector less attractive to such "dinner party" landlords, paving the way for larger institutions to grab market share.

Buy-to-let investors purchase residential property, typically with a mortgage, with the aim of renting it out.

OneSavings Bank reported a 17 percent increase in its loan book for the first nine months of the year and said net loans and advances grew by 997 million pounds to 6.9 billion pounds in the period.

(Reporting by Noor Zainab Hussain and Radhika Rukmangadhan in Bengaluru; Editing by David Goodman)

Stocks treated in this article : OneSavings Bank PLC, CYBG