* FTSEurofirst 300 rises 1.7 pct, hits seven-year high
* Athens index rises ahead of vote, led by banks
* European shares enjoy best week since 2011
* Cyclical stocks such as carmakers among top gainers (Adds detail, quote)
By Alistair Smout
LONDON, Jan 23 (Reuters) - Greek shares led euro zone stock markets higher on Friday, boosted before Sunday's pivotal elections by the European Central Bank's decision to buy government bonds.
European shares were set for their biggest weekly gain in over three years as investors cheered the ECB's quantitative easing programme to battle deflation.
The bond-buying scheme helped Greece's ATG share index rise 6 percent, with Attica Bank, National Bank of Greece and Piraeus Bank up between 14 percent and 11 percent.
Traders also saw a greater chance that anti-bailout party Syriza, currently leading in the polls, would reach a compromise with Greece's official lenders if they came into power.
Greece will be eligible for the ECB bond-buying programme but subject to stricter conditions because of its bailout plan.
"The ECB have thrown a carrot to Syriza, saying that if you complete the review and agree with the troika