Image copyright Oli Scarff

UK and European banks have failed to sell any so-called Coco bonds this year amid worries about the health of the banking sector.

Cocos - short for contingent convertible bonds - are turned into shares if a bank starts to struggle.

European banks raised around €45bn from the bonds last year.

But in 2016 none have been issued, according to data company Dealogic, amid wider investor fears about investing in banks.

Last week, European Central Bank president Mario Draghi sought to calm fears that banks would not have enough capital to cope with another financial crisis.

Coco collapse

Cocos are seen as riskier than traditional bank bonds because they offer lenders less security.

"European Banks Coco Bond Sales 2016: €0bn; 2015: €45bn; 2014: €46bn; 2013: €27bn; 2012: €5bn," tweeted Lawrence McDonald, a financial consultant and former Lehman Brothers executive.

Banks had planned to issue €40bn of Coco bonds this year, according to Dealogic.

That leaves them facing a financing gap at a time when analysts are warning that Europe's banks must also deal with rising costs and slowing revenue.

Bank results

Three of the UK's biggest banks - HSBC, Lloyds and Royal Bank of Scotland - will report their company results for 2015 this week.

Analysts forecast costs will rise at all three, partly due to the UK bank levy and high bills from mis-sold Payment Protection Insurance (PPI).

Reports also suggest Standard Chartered, the Asia-focused UK bank, will reveal it has fallen into the red when it publishes results on Tuesday.