The central bank expects inflation to remain around its 3 percent target this year.
Earlier on Friday, the central bank sold US$200 million in two auctions.
Mexican growth slowed in the fourth quarter due to flat industrial activity.
The central bank sold the dollars at an average weighted price of 18.4399 pesos per dollar.
The peso weakened to 18.2050 per dollar on Friday morning.
The Mexican central bank governor said an expected acceleration in the U.S. economy should fuel a pick-up in Mexican exports.
Mexico's central bank said in a statement that it reserved the right to change its calendar in case it needs to take into account "extraordinary events."
The auction is part of an program to boost foreign exchange liquidity.
The peso has lost about 10 percent of its value against the dollar so far this year.
Central Bank board members voted 3 to 1 at their July 30 meeting to hold their benchmark rate at a record low of 3.0 percent.