Eric Moussambani, who became an overnight celebrity at the Sydney Games in 2000 when he slowly made his way through a 100 metres freestyle heat, was appointed by the country's Olympic committee earlier this month, the government website www.guineaecuatorialpress.com said.
Moussambani will combine his job in the oil industry with his coaching duties, the website said.
"Even today (he) still receives requests on our website requesting interviews," it added.
It is not certain how many swimmers will travel from the small African nation to London for the Games which start on July 27.
It is a turn around in fortunes for Moussambani, who had complained of being shunned and ridiculed in Equatorial Guinea after becoming a cult figure around the world for his Olympic endeavours and lack of swimming acumen.
In Sydney, Moussambani swam his heat on his own after the other two competitors were disqualified for false starting.
Having never swum competitively in a 50-metre pool, Moussambani flagged near the end of his solo heat and appeared to almost sink as he approached the finish.
Roared on by the 17,000-strong crowd, his time of 1:52.72, was the slowest seen at an Olympics and more than a minute behind the world record. But he received a standing ovation and instant fame as reporters dubbed him 'Eric the Eel'.
It was then discovered Moussambani had only been swimming for eight months and trained in a 20-metre hotel pool.