LONDON/FRANKFURT (Reuters) - Deutsche Bank DKBGn.DE shares extended losses on Tuesday on investor doubts that its chief executive can revive the lender by shrinking the investment bank and returning to its roots as banker to corporate Germany.

Christian Sewing, CEO for just over a year, and his finance chief are on week-long roadshow to explain the restructuring. To underline his commitment, Sewing plans to invest a quarter of his fixed salary -- around 820,000 euros -- in Deutsche shares, a person with knowledge of the matter said.

Deutsche’s stock price has fallen 10 percent since Sunday’s restructuring announcement to cut 18,000 jobs in a 7.4 billion euro ($8.3 billion) “reinvention”. It is the biggest two-day decline in almost three years.

By 1312 GMT, shares were down 3.8% on the day, after sliding as much as 6.5% earlier. The bank’s bonds also fell.

Analysts and investors say Sewing, who joined Deutsche Bank in 1989, is right to cut back its trading desks but question if he can make his plan work when interest rates are still low and U.S. banks have expanded their share of the German market.

“There seems to be some concerns around the plan details, particularly the ability for the bank to retain revenues while cutting costs,” one of the bank’s top 25 shareholders told Reuters, citing worries the bank would need fresh equity to execute Sewing’s plan.

Analysts with RBC Capital Markets wrote that the bank’s outlook for revenue growth was “ambitious” and there was a high degree of risk associated with implementing the plan.

Ratings agency Fitch, which last month downgraded the bank to “BBB” status, the lowest investment-grade, echoed this.

“Cutting back volatile, capital-intensive and underperforming sales and trading activities, and further reducing the cost base should improve profitability and strengthen leverage, but execution risks are high,” it said.

The logo of Deutsche Bank is pictured on a company's office in London, Britain July 8, 2019. REUTERS/Simon Dawson

JOB CUTS

Deutsche plans to return closer to its roots by focusing on corporate banking and asset and wealth management, areas that can offer more stable revenues than investment banking but are increasingly competitive.

The bank began cutting jobs in its trading business on Monday, with staff laid off in offices stretching from Sydney to New York.

Sewing, promising to make a break with a past of Deutsche’s “over-promising and under-delivering”, told analysts on Monday that his plan was a “real game changer”.

At least one big investor is sold on the proposals.

Douglas Braunstein, who holds an 3.1% share in Deutsche through his New York-based Hudson Executive Capital, said it would take a while for the market to appreciate what Deutsche Bank is doing.

“Going back to basics for this 150-year old company is ultimately going to be a very successful strategic decision,” he said on CNBC.

However, Deutsche Bank's capital instruments took a further hit on Tuesday, with a US dollar Additional Tier 1 (AT1) perpetual instrument callable in Nov 2021 dropping as much as 2.4 cents on the dollar to 84.62; setting the yield at a hefty 30.4%. DE107155147=

The euro-denominated debt also suffered losses with a perpetual AT1 bond callable in May 2027 falling 1.5 cents to 86.56, with the yield rising to 11.89%. < DE107205454=>