Alcatel bought the 34% stake it did not already own in a 3G mobile technology joint venture with Japanese group Fujitsu, an AFP report said.
The AFP report said the French company, which confirmed the sale in a report in French business daily Les Echos, declined to give financial details for the deal involving the joint venture Evolium.
Evolium was created in 2000 when Alcatel was looking to take advantage of Fujitsu's advance in UMTS mobile technology.
Alcatel has been linked with other possible partners in third-generation mobile technology, notably with the Canadian equipment maker Nortel, the AFP report said.
An Alcatel spokesman, quoted by AFP, said the group was considering all its options as it sought to reinforce its position in the sector.