Brit Insurance has become the latest insurer to join Imarket.
The move comes weeks after the decision by MMA and Fortis to back the industry e-trading initiative.
There will be at least three Brit Insurance products live on Imarket by the end of the year. Directors' & officers' cover will be the first product, currently only available via two other insurers; with professional indemnity and fleet following.
Simon Cooter, head of UK distribution for Brit Insurance, said: "Our commitment to the Imarket initiative, means that we are not only providing another method of accessing Brit Insurance's products to our existing broker panel, but also providing access to those with whom we do not currently deal.
"Brit Insurance has strong ambitions for business growth in the SME sector; recognising the significant opportunity to offer convenience and choice to brokers utilising electronic trading, and Imarket is a good example of a system which saves the broker time, money and hassle."
Peter Knowles, strategy and marketing director, Polaris UK, added: "We are delighted to welcome another major commercial insurer to Imarket, bringing the total number of insurers and underwriting agencies now involved to 13.
"Following hard on the heels of MMA and Fortis joining last month, it's great news for imarket and even better news for the 2,600 Imarket registered brokers.
"With insurers adding more products to the quote facility every month, the choice for brokers is increasing at a rapid pace and Brit Insurance will be another valuable addition over the coming months."