MEXICO CITY, Oct 23 (Reuters) - Mexico's Grupo Bimbo , the world's largest breadmaker by volume and sales, on Thursday said its net profit jumped 20 percent in the third-quarter from a year ago on better operative performance and a lower effective tax rate.

The company, which manufacturers Thomas' English Muffins and Orowheat bread among other products, reported a profit of 1.92 billion pesos ($142.8 million), compared with 1.6 billion pesos in the year-earlier period.

Bimbo's revenue for the quarter rose 11.9 percent to 50.2 billion pesos.

Shares in Bimbo closed up 2.24 percent at 40.12 pesos. The results were reported after trading ended for the day.

($1 = 13.4235 pesos at end-Sept) (Reporting by Gabriel Stargardter and Elinor Comlay; Editing by Alan Crosby)