Manpower said more employers were planning to recruit staff in the coming months than lay workers off.
Hiring intentions in London were said to be the best for five years, according to a survey of more than 2,000 UK employers.
The report predicted that construction might start to dig itself out of the recession which has gripped the sector for the past five years.
Mark Cahill, managing director of Manpower, said an improvement in construction jobs was vital because its performance has been a "huge drag" on the economy.
"There are more cranes on the London skyline than in the rest of the country put together, but technology, media and advertising are also fuelling job prospects in the capital."
Mr Cahill said 2013 was turning into a "solidly optimistic" year after two years of recruitment "bumping along the bottom".
Engineers and other skilled workers were in demand, but companies such as supermarkets were also recruiting new staff, according to the study.