Britain's Barclays (BCS) - Get Report beat expectations for first-half earnings from its core business on Friday, indicating that long-sought-after restructuring benefits are beginning to feed through.

Profit before tax from the group's core business, which includes the retail, commercial and investment banks as well as the credit-cards business, rose by 18.5% to £3.9 billion ($5 billion). Losses before tax in the non-core division widened to £1.9 billion from £745 million one year ago.

Recently arrived  CEO Jes Staley, a former J.P. Morgan (JPM) - Get Report banker,  said: "This has been a quarter of very encouraging progress against our strategy."

Barclays shares rose by as much as 6% in London trading, to reach a post-Brexit peak of 157.0 pence, although the stock is still down by around 27% so far this year.

Investors have long been concerned about the slow pace of Barclays' restructuring since the financial crisis, although chairman John McFarlane and Staley have this year started to speed up selloffs.  Concerns about Barclays were recently exacerbated by Britain's vote to leave the EU, which could affect Barclays corporate and investment banking operations on mainland Europe.

Barclays return on tangible equity in the core business fell to 10.8% in the first half, from 13.7% a year ago. 

Return on tangible equity at the group level was 4.8%, against 6.9% one year ago. The group's leverage ratio, a key regulatory measure of its capital base, fell from 4.5% at the end of 2015 to 4.2% at the end of June after the group's balance sheet expanded during the period. 

The group benefited from a £1.5 billion reduction in the value of conduct and litigation costs during the period, although this was not enough to offset the effect of widening losses in the non-core portfolio. That led to group-wide profit before tax to fall 20% to just over £2 billion.

The deterioration of the non-core result was driven by a £424 million write-down of an education, social housing and local authority loan portfolio and a £372 million charge against the French business that Barclays put up for sale.

Analysts at Jefferies were unconvinced by the first-half numbers, instead choosing to reiterate their under perform rating, citing the current valuation of the shares, as well as a backward movement in the group's so- called leverage ratio. They affirm their price target of 115.0 pence for the stock, which implies a downside of 26% from current levels.