Frontrunning Formula Renault team Koiranen Motorsport will replace Ocean Racing Technology in the GP3 Series from next year.
The championship, which will introduce its second-generation car for the 2013 season, announced its line-up of teams on Monday.
The grid will remain at nine teams as it was this campaign, but with ex-Formula 1 driver and World Touring Car Championship race winner Tiago Monteiro's Ocean squad making way for the Finnish Koiranen outfit.
GP3 CEO Bruno Michel said: "We have received a lot of requests from some of the best motorsport teams which proves once again that GP3 generates a lot of interest.
"We have chosen to stay loyal to most of the existing GP3 teams but we thought it was also important to bring fresh blood into the mix.
"We are happy to welcome Koiranen Motorsport, who have been very successful in other categories. It will be very interesting to see how these teams will adapt to the new GP3/13 car."
Koiranen has enjoyed a lot of success in Formula Renault 2.0 in recent years. It won the Formula Renault Eurocup in 2010, and has twice landed the competitive NEC crown as well. In 2011 it won the teams' championships in both series, and it is currently fighting for the Eurocup and ALPS titles with Red Bull junior Daniil Kvyat.
AUTOSPORT understands that Ocean's commitment to GP3 was always likely to be a short-term deal. The team joined the series for the final year of the 2010-2012 contract cycle, filling the void left by Tech 1 Racing.