JOHANNESBURG (Reuters) - South Africa's rand gained more than 1 percent against the dollar on Monday, boosted in large part by a slight but unexpected trade surplus for November. By 1622 GMT the rand was trading at 10.4265 to the greenback, a 1.1 percent gain over Friday's close. The local currency recovered from a session low of 10.5445, albeit in thin year-end volumes, after data from the revenue service showed a 770 million rand trade surplus in November. This compared with a 12.39 billion rand deficit the previous month. Persistent trade deficits have resulted in a yawning current account deficit of nearly 7 percent of GDP, a longstanding source of weakness for the rand. "A gradual (trade balance) improvement is expected as 2014 progresses, provided the global environment is favourable and local production picks up," Nedbank said in a comment. Government bonds however slumped on Monday, with foreign demand for local debt tapering off as the year draws to a close. The yield for the benchmark 2026 note climbed 8 basis points to 8.265 percent while that for the 2015 paper was up 7.5 basis points at 6.155 percent. Foreign flows into the debt market, key to plugging the current account deficit, have waned in recent weeks, with offshore investors selling more than 631 million rand worth of bonds last week, according to data from the JSE exchange.