Nationwide warns new bank tax puts lending at risk

* Tax equivalent of capital to fund 10 bln pounds lending

* CEO says should be different tax regime for mutuals

* First (Other OTC: FSTC - news) -quarter underlying profit up 52 percent

* Net tax cost to rise to 90-100 mln pounds in 2016/17 (Adds CEO comments from interview)

By Matt Scuffham

LONDON, Aug 18 (Reuters) - Britain's biggest customer-owned lender Nationwide said a new banking tax will cost it 300 million pounds ($470 million) over the next five years and potentially hurt lending.

Nationwide, Britain's second biggest provider of home loans, said the tax cost was the equivalent of the capital required to fund 10 billion pounds worth of lending.

Chief Executive Graham Beale warned that the introduction of a new surcharge on profits from next year, announced by Finance Minister George Osborne last month, would have a disproportionate impact on building societies, which are smaller than major banks and focus on domestic lending.

"This represents a missed opportunity to support diversity by acknowledging that building societies are different to banks and to recognise the contribution Nationwide and other mutuals make by lending to the UK economy, and the housing market in particular," Beale said in a statement accompanying the lender's quarterly results on Tuesday.

Nationwide paid 28 million pounds in tax under Britain's existing bank levy in the 2014/15 tax year.

In an interview with Reuters, Beale said the new surcharge would see its net tax cost rise to between 90 million and 100 million pounds in the 2016/17 financial year, the first in which the new rules will have a full impact.

CAPITAL STRENGTH

Beale said customer-owned lenders such as Nationwide should be treated differently to banks because they are less of a risk to the British economy.

"Instead of having a surcharge of 8 percent for the large mutuals, to acknowledge that we're different with a different risk profile, it could have been 4 percent," he said.

Nationwide reported a 52 percent increase in first-quarter underlying profit to 400 million pounds and a 50 percent rise in statutory profit to 379 million.

It (Other OTC: ITGL - news) provided more than a quarter of overall net lending to the British housing market during the period. Nationwide's gross mortgage lending rose 17 percent to 6.8 billion pounds and net lending climbed 23.5 percent to 2.1 billion pounds.

Nationwide is targeting a 10 percent share of Britain's personal current account market. Its share remained unchanged at 6.8 percent in its first quarter, which started in April.

Nationwide said its core tier 1 ratio, a key measure of financial strength, rose 1 percentage point to 20.8 percent, higher than any British lender. Its leverage ratio strengthened 10 basis points to 4.2 percent. ($1 = 0.6389 pounds) (Editing by Sinead Cruise and David Clarke)