Britons' employment prospects are at their bleakest in three years, a quarterly survey by recruitment firm Manpower suggested on Tuesday, with employers planning no net increase in jobs over the next three months.

Manpower's seasonally adjusted employment outlook balance fell to zero for Q1 2012, the lowest reading since that for Q4 2009 and down from +1 percent for Q4 2011.

That spells bad news for the 2.62 million Britons looking for work. The jobless rate hit a 15-year high of 8.3 percent in the three months to September and is forecast to rise further when October data is released on Wednesday.

The 2012 jobs market sits on a knife edge, said Manpower's UK managing director Mark Cahill. Employers have now adopted a wait-and-see approach to hiring; they are cautious about the economy and the fear of a euro-wide contagion is weighing heavily on their minds.

Markets are likely to judge measures agreed at last week's EU summit as too little too late to solve the raging debt crisis in the euro zone. The 17-country single currency zone is Britain's main trading partner and about 3 million jobs depend on trade with Europe, according to the government.

The Manpower poll showed that hiring plans for the first quarter varied widely by sector. Construction was the most pessimistic, recording a -2 percent balance, the biggest rate of net job cuts. Utilities companies were the most optimistic, with a 13 percent balance of firms saying they would create jobs.

Manufacturers, too, showed tentative signs of confidence, with their employment outlook balance coming in at 5 percent and chiming with recruitment findings in a recent survey by the EEF, the main trade body for manufacturers.

However, employment intentions in the key finance and business services sector flatlined, down from a reading of 5 percent for the final quarter of this year and a strong level of 10 percent a year ago.

(Reporting by Olesya Dmitracova)