(Updates with details, context)
MEXICO CITY, Dec 24 (Reuters) - Mexico's economy contracted by 0.5% in October from September in seasonally adjusted terms, making a poor start to the fourth quarter after nine months of stagnation, figures from the national statistics agency showed on Tuesday.
The decline in economic output was the biggest since a 0.5% contraction in March, and the third negative reading in four months, according to the data from the agency known as INEGI.
Mexico's economy has struggled to gain traction under President Andres Manuel Lopez Obrador, who took office in December 2018 pledging to ramp up growth to 4% per year.
Instead, the economy has been flat this year, slipping into a mild recession in the first half of 2019.
Compared with the same month a year earlier, economic activity shrank by 0.8% in unadjusted terms in October, the figures showed. (Reporting by Dave Graham; Editing by Alison Williams)