Credit Suisse has upgraded Greek equities to "benchmark" from "underweight", citing cheap equity valuations and a range of supportive macroeconomic factors, according to a Reuters report on Tuesday.

The broker pointed to a projected cyclically adjusted budget surplus in 2011; the lowest private sector debt-to-GDP ratio in Europe; an already pessimistic economic growth forecast; low leverage in Greek banks; and a good chance the maturity of Athens' EU/IMF financial aid package will be extended.

Greece's leading share index .ATG is up 3.5 percent on Tuesday after gaining 12.7 percent last month. The index lost nearly 36 percent last year on concerns over its ability to finance itself sustainably.

Shares on the Athens Stock Exchange rallied 4.4 percent on the news on Tuesday, outperforming major European markets.