The shareholder payouts, which would bring the three-year tally to more than 2 billion pounds, coincide with 3i boosting investment by 35% to 1.6 billion pounds in the 11 months to February 28 from the same period inn 2006.
The London-based firm, which focuses on the middle market, has been expanding the types of investments it makes, to include infrastructure, and where it invests, to include Asia.
3i, said in a trading statement ahead of full-year results due on May 10, that realisation proceeds totalled 1.948 billion pounds in the 11-month period, a 7% gain compared with 1.815 billion in the same period in 2006.
Our announcement, concerning a further return of capital, reflects the continued delivery of strong realised returns whilst still allowing for planned growth in the future, chief executive Philip Yea said.
3i shares were up 2% at 1,160 pence, when the FTSE 100 index was up 0.3%.
The payout is expected to be made using the same method as that used in 2006- a bonus issue of preference shares and subsequent purchase offer.
3i chief financial officer, Simon Ball, said the returns have come amid a period of record realisations and cautioned that, one has to be realistic about the ability to sustain such levels.
3i earlier in March agreed to buy British maintenance and support service firm Enterprise for 486 million pounds and to sell the car parking facilities of Britains National Car Parks for 790 million pounds.
Ball declined to comment about whether 3i might submit a counterbid for estate agency owner Countrywide Plc, which has a 1 billion pound offer from private equity firm Apollo Management. An earlier offer from 3i was rejected. 3i also listed an infrastructure fund earlier in March, which raised 700 million pounds, at the bottom end of the range the company had anticipated. We cant find a larger listed infrastructure fund in Europe, Ball said, when asked if he was disappointed about the IPO, which came during a volatile stretch for markets.