Two more names surfaced Thursday as candidates for the Liberal Democratic Party presidential election as economy minister Kaoru Yosano and former LDP policy chief Nobuteru Ishihara both indicated they were willing to run.

The shock of Prime Minister Yasuo Fukuda's sudden resignation announcement Monday has already worn off in Tokyo's political battleground of Nagata-cho, and all eyes are now fixed on the Sept. 22 presidential election, which will automatically pick the next prime minister.

The LDP-New Komeito ruling coalition is also considering dissolving the Lower House in October for a general election in November, sources said Thursday.

For president, LDP Secretary General Taro Aso, 67, is the presumed favorite, but Yosano, 70, minister of economic and fiscal policy, told ex-Prime Minister Yasuhiro Nakasone on Thursday that he intended to run for the top post. Yosano once was Nakasone's aide.

Former Defense Minister Yuriko Koike, 56, and Ishihara, 51, son of outspoken Tokyo Gov. Shintaro Ishihara, are also leaning toward throwing their hats in the ring.

"Many people have given me words of encouragement to actively engage" in the presidential poll, Koike said Thursday afternoon. "I would like to prepare the surrounding environment" for the candidacy.

Ishihara was more blunt.

"I think that we must avoid a situation in which no one else but Aso runs for president," he said. "It seems like Yosano is considering running and I would like to make efforts as a midechelon lawmaker to make sure the presidential election is full of lively discussion."

Ishihara said, however, that he had not begun to collect the 20 recommendations necessary to enter the election.

During lunchtime in Nagata-cho, the LDP factions held their weekly lunch meetings simultaneously. Whenever a presidential election takes place, the factions start scheming over candidates.

Last year, when Fukuda ran successfully against Aso, most of the factions backed him. This year, however, things aren't so simple.

The largest faction, led by Chief Cabinet Secretary Nobutaka Machimura, is in a dilemma because Fukuda and his quick-to-resign predecessor, Shinzo Abe, are from that faction. So is Koike.

The group's honorary chairman, ex-Prime Minister Yoshiro Mori, has reportedly said he will decide on everything from whether the faction should back a member or even vote for a specific person as one when all the candidates have announced their bids.

Ishihara belongs to a midsize faction led by former LDP Vice President and Secretary General Taku Yamasaki. Former trade minister Akira Amari, who also belongs to the Yamasaki faction, has already voiced his support for Aso, and Yamasaki is set to back a candidate after speaking with Ishihara on Friday.

INFORMATION FROM KYODO ADDED.