* Bachelet begins second term with reform agenda
* Bachelet will accept sash from Salvador Allende's daughter
* South American ministers to discuss Venezuela unrest
By Rosalba O'Brien
SANTIAGO, March 11 (Reuters) - Michelle Bachelet will take over the presidency of Chile on Tuesday in a ceremony loaded with symbolism, promising to stick to her tax-and-spend campaign pledges despite a sharp economic slowdown.
Bachelet will accept the presidential sash from Senate head Isabel Allende, the daughter of deposed socialist president Salvador Allende, whose overthrow in 1973 ushered in the seventeen-year dictatorship of Augusto Pinochet.
Returning to Chile's top job after a spell with the United Nations, Bachelet heads a coalition that ranges from moderate leftists to communists. She wants to address social inequality in the top copper exporter by overhauling education and healthcare, funded by tax reforms.
"From day one I will work to fulfil the promises we made," said Bachelet in an interview with local TV channel Canal 13 last week.
But as well as a prickly Congress and a volatile student movement that has been vociferously demanding better, free education, she will have to deal with a struggling economy. Economic activity growth slowed to a near four-year low in January and a falling copper price and weakening peso are taking their toll.
Her swearing-in in the port city of Valparaiso, the seat of Chile's Congress, will be attended by presidents from around the region, with the notable exception of Venezuela's Nicolas Maduro, who was due to come but cancelled at the last minute, according to local media.
An emergency meeting of South American foreign ministers, including Venezuela's Elias Jaua, is planned for Wednesday in Santiago to discuss civil unrest in Venezuela, where at least 22 people have died as opposition street protests for over a month have demanded Maduro's resignation.
In a possible reflection of the strategic importance of Chile - a non-permanent member of the U.N. Security Council - U.S. vice-president Joe Biden is in Santiago to attend the ceremony. He has been meeting with Bachelet and other Latin American leaders and as well as the troubles in Venezuela is expected to discuss the TransPacific Partnership free trade agreement.
Chile and the United States are among the 12 countries involved in TPP talks, though disagreements between some partners have delayed a final deal.
The 1973 coup and the years of repression that followed have left unresolved issues in Chile, with the fortieth anniversary last year inflaming sensitivies just as the election campaign was getting going.
Salvador Allende committed suicide as airforce jets strafed La Moneda presidential palace on Sept 11 1973.
Many of his supporters fled into exile as the military cracked down on dissent, including both his daughter Isabel and a young Michelle Bachelet, who was temporarily imprisoned and tortured.
Isabel Allende (not the Chilean author, who is a distant relative) is now a Socialist Party politician and was named as the first female head of Chile's senate last month.
In that role she will hand the sash on Tuesday to Bachelet, who led Chile as its first female president between 2006 and 2010.
Barred constitutionally from immediate re-election, the popular and charismatic Bachelet easily beat the right-wing candidate when she returned to fight the 2013 presidential vote. She is the first Chilean leader to serve a second term since the return to democracy, and will take over from unpopular conservative President Sebastian Pinera.
Between presidential terms, her activities included heading UN Women, a newly created U.N. entity which promotes gender equality.
(Addititional reporting by Alexandra Ulmer and Antonio de la Jara Editing by W Simon)