(Adds comments from minister's news conference)
By Marcela Ayres and Patricia Duarte
BRASILIA/SAO PAULO, April 6 (Reuters) - Brazilian Finance Minister Henrique Meirelles resigned on Friday to weigh a presidential bid in the October elections for the ruling MDB party that will depend on whether President Michel Temer decides to run.
"I decided to leave now. I will study a possible candidacy," he told Reuters in a WhatsApp message, without elaborating.
Meirelles later told reporters at a news conference that he will be succeeded by his deputy minister Eduardo Guardia, who is expected to continue his efforts to rein in the budget deficit and restore confidence in the management of Brazil's economy.
Meirelles, 72, a former banking executive and central bank governor, ruled out being Temer's vice presidential running mate.
Temer is currently the candidate of the Brazilian Democratic Movement party (MDB), Brazil's largest, Meirelles said, and the two will "reach a conclusion" at a later date on who will run.
Temer has been polling in the low single digits in recent surveys and members of his party fear he might not be a viable candidate. The party will decide at a convention in June.
If Temer's approval rating does not improve by then, Meirelles would be the government's presidential candidate, Temer aides told Reuters last week.
Meirelles said he helped Temer's government recover Latin America's largest economy from its worst recession and bring inflation under control with policies that must be continued. The priorities, he said, are to overhaul a costly social security system, reform a complex tax system and privatize state-run Eletrobras, the country's biggest utility.
On Tuesday, Meirelles joined MDB at an event that felt like the possible prelude to a launch of a Temer-Meirelles ticket, with a large photo of the two men and a campaign jingle playing loudly.
Meirelles previously belonged to the Social Democratic Party (PSD), a partner in Temer's coalition government, but left after it became clear the party planned to back Sao Paulo Governor Geraldo Alckmin in his presidential run. (Additional reporting by Patricia Duarte; editing by Rosalba O'Brien and James Dalgleish)