By Miguel Gutierrez, Michael O'Boyle and Dave Graham MEXICO CITY (Reuters) – Mexico's Senate on Thursday made new cuts to a tax reform plan that President Enrique Pena Nieto proposed to increase the nation's anemic tax take, sending the bill back to the lower house of Congress for final approval. The bill, which includes higher taxes for the rich as well as levies on junk food and on stock market gains, is a cornerstone of a wider economic reform agenda that Pena Nieto is pushing to lift lackluster growth in Latin America's No. 2 economy. After conservative opponents walked out of the Senate, refusing to support the legislation, ruling party leaders struck a deal with leftist lawmakers on changes to income tax rates that would lower the bill's projected tax take. Pena Nieto's Institutional Revolutionary Party (PRI) lacks a majority in Congress and is banking on help from the conservative National Action Party (PAN) to push through the energy reform, which aims to lure investment into the state-controlled sector and help reverse a slide in oil output.