Hargreaves Lansdown assets boosted by market gains, net inflows

* Total assets up 13.9% to 97.8 bln stg

* Market gains add 9 bln stg, new business 2.9 bln

* CEO says confident on outlook (Adds detail from statement, bullet points)

By Simon Jessop

LONDON, May 15 (Reuters) - British fund supermarket Hargreaves Lansdown on Wednesday posted a 13.9% rise in assets in the first four months of 2019, boosted by market and new business gains.

Hargreaves, which offers a range of financial services to largely UK retail customers, said a slow start to the year had picked up into April as clients looked to make use of their tax-free savings allowance before the end of the financial year.

Total assets under administration at the end of April were 97.8 billion pounds ($126.26 billion), up from 85.9 billion at the end-December, it said in a statement. Market gains added 9 billion pounds and new business 2.9 billion pounds.

New business wins were driven by an increase in the number of new clients, wealth consolidation onto platform from existing clients, flows into its cash management service and an asset transfer of old business from Witan Investment Services.

Hargreaves has benefited as other investment firms look to move groups of old retail client business off their books as the costs of managing smaller client portfolios rises.

As well as Witan, Hargreaves has also agreed to take on business from JP Morgan and Baillie Gifford, with most of their clients and respective assets expected to arrive in the early months of the next financial year, it said.

The rising level of group assets and higher cash revenue margin helped net revenues rise 8% to 159.5 million pounds in the period, more than offsetting a fall in revenues from stockbroking, it said.

"Whilst political and macro-economic uncertainty remains, we are confident that our continued focus on the needs of UK investors and savers means that we are well positioned to deliver attractive growth," Chief Executive Chris Hill said.

($1 = 0.7746 pounds) (Reporting by Simon Jessop; editing by Sinead Cruise)