Alviro Petersen, the South Africa opener, will join Somerset as their overseas player for the first part of the 2013 season. Petersen, who has previously played for Essex and Glamorgan, will be available until the start of the Friends Life t20 competition.

Petersen, 31, is currently on tour with South Africa in Australia, making 64 on day one of the first Test. He scored 241 runs at an average of 61.00 during South Africa's 2-0 Test series win in England early this year, including his Test-best score of 182, and has accumulated almost 10,000 first-class runs at just under 40 in his career.

"I am very pleased to have signed to play for Somerset for the first part of next season," Petersen said. "Somerset are a successful team in all forms of cricket and I look forward to becoming part of the set-up and hope that I can help them to win some trophies in 2013."

South Africa have a light schedule next year, with their Test series in Sri Lanka having been put back until 2015, and their Test captain, Graeme Smith, has already signed for Surrey. Petersen could be involved for the ODI leg of the tour to Sri Lanka, still scheduled for July 2013, although his last one-day appearance came in January.

Petersen will follow in the footsteps of compatriot Vernon Philander, who played five Championship matches for Somerset at the start of 2012, as well as Smith, who led the county to their most recent silverware in winning the Twenty20 Cup in 2005. South Africa's Richard Levi and Albie Morkel also turned out at Taunton last season, in the FLt20, with Pakistan spinner Abdur Rehman replacing Philander during the second half of Somerset's Championship campaign.

Somerset will be Petersen's third county in three seasons. He captained Glamorgan in 2011 but abandoned a plan to play for them as a Kolpak signing this year, having been recalled by South Africa. A move to Essex then sparked anger at the Welsh county; a century on his return to Cardiff was Petersen's response.

"We are delighted to have signed Alviro Petersen," Guy Lavender, the Somerset chief executive, said. "He is an exceptional player and has an impressive record, which he demonstrated during this summer's series against England and we look forward to welcoming him to Taunton in the spring."