X maker SSL has paid around £140m to up its stake in Russian condoms packager and distributor BLBV to 75 per cent.
The firm, which also makes Scholl footcare products, said it had agreed an option to buy the rest of the business next year.
Garry Watts, SSL's chief executive, said: "We have been delighted with our investment in BLBV.
“The underlying performance of the business since our partnership began has exceeded all our expectations.
Together with BLBV's existing shareholders and management, we have made excellent progress in bringing our businesses together.
"We are very optimistic for BLBV's prospects and the potential for SSL's products within the CIS and Eastern Europe.
"We are pleased to have reached an agreement which allows us to strengthen our control of BLBV in a staged and balanced manner."