By Nigel Stephenson
LONDON (Reuters) - Traders at some of London's biggest banks will be at their desks on Sunday for Greece's cliffhanger referendum but, in line with market reaction to the crisis so far, the degree of reinforcement is likely to be modest.
Citi, Barclays (LONDON:BARC), Deutsche Bank (XETRA:DBKGn) and JPMorgan (NYSE:JPM) are among banks bringing in staff for the crucial hours around the result of the Greek vote, which will close at 5 p.m. London time (1600 GMT) unless an extension is announced. The first exit polls are expected soon after, and first official projections of the result at around 1800 GMT.
"Between London and Asia, you will have coverage on the relevant trading desks – Sunday night in London, while for Asia it will be a slightly early morning for them. Not huge amounts, just a handful of staff in case clients need something," a spokesperson at JPMorgan said.
Barclays said research, sales and trading staff would monitor the referendum over the weekend.
"The FX teams will be in the office from 5 p.m. on Sunday afternoon to follow developments," a spokesman said.
London staff would overlap with Asian trading, which would start at 0130 GMT on Monday.
Other major banks, including HSBC and UBS, will mostly be relying on traders in their Asian offices.
The referendum result is highly uncertain, with polls suggesting the 'Yes' and 'No' camps are evenly split.
"I will be toiling away on the sofa with a cup of tea and my iPad throughout the night," said Simon Derrick, head of FX research at BNY Mellon. "But I could be in bed by 11 p.m. on Sunday night if it all sorts itself out."
Prime Minister Alexis Tsipras has called for a 'No' vote rejecting reforms demanded by international creditors in exchange for vitally needed funds.
Greece has already defaulted on an International Monetary Fund loan and failure to agree terms could ultimately see it leave the euro zone.
Contagion from Greece to other countries has been limited, as the bulk of its debt is now in the hands of governments or multinational lenders. While the yield premium that investors demand to hold Italian or Spanish bonds rather than low-risk German benchmarks has widened this week, the moves have been nothing like as big as in previous flare-ups in the crisis in 2011 and 2012.
London traders and other bank staff have been called in for a few Sunday shifts in recent months, including last September's referendum on independence for Scotland and this May's British general election.