3i's investment in discount chain Action rose to 2.3 billion pounds ($3.26 billion) from 2 billion pounds three months before. Action's sales rose 28 percent in 2017 and 244 new stores were opened in the year.

Action will be publishing its audited results for 2017 in March, 3i said. Its board has launched a new refinancing with a view to pay its shareholders before March 31.

In a statement, the group said its private equity cash realisations were 389 million pounds in the nine months to 31 December 2017.

The listed private equity group's total return was 19.4 percent for the nine months to Dec. 31, 2017. Its share price has risen more than 30 percent in the last 12 months.

(Reporting by Dasha Afanasieva; editing by Simon Jessop and Jason Neely)