* Laschet calls Monday evening meeting of CDU board
* Soeder says the CDU must decide on chancellor candidacy
* Says he would accept CDU board decision for Laschet
* Greens agree candidate while conservatives rift remains (Recasts with Soeder)
By Caroline Copley and Paul Carrel
BERLIN, April 19 (Reuters) - Bavarian premier Markus Soeder said on Monday it was up to Germany's Christian Democrats to decide whether he or their party leader should run as the conservative candidate for chancellor, and that he would accept a decision for his rival.
Christian Democrat (CDU) Chairman Armin Laschet and Soeder, who leads the CDU's Bavarian sister party, have been unable to resolve their week-long stand-off over who should be chancellor candidate for their conservative alliance, dubbed 'the Union'.
With CDU Chancellor Angela Merkel stepping down after a Sept. 26 election, pressure is mounting on the bloc to agree on a candidate as its ratings wallow near a one-year low, hurt by the government's chaotic handling of the COVID-19 pandemic.
Laschet said he had invited Soeder to a 6 p.m. (1600 GMT) meeting of the CDU's federal board on Monday at which Laschet would present a plan to decide which of them runs as chancellor candidate for their conservative alliance.
Soeder declined the invitation, saying he did not want to "interfere", and put his fate in the CDU's hands.
"If the CDU makes a clear decision tonight, then we would accept that," the Bavarian told a news conference in Munich.
"The CDU is the stronger and bigger sister and only they can decide if this broad majority is there or not. We can only make an offer, and that's what we've done now."
Pressure grew on the conservatives to resolve the row as the Greens, without showing any internal wrangling, named co-leader Annalena Baerbock as their candidate and she vowed to seek the chancellery for the first in the party's 40-year history.
The conservatives retain a narrow lead in polls over the Greens, but the leadership rift threatens to loosen their 16-year-old grip on power as they prepare to fight the election without Merkel, who has won them four consecutive victories.
"The time for decision is here," Soeder said of the conservative candidacy.
Laschet said he would make a proposal to the CDU board on how to resolve the matter, adding: "I hope that we can come to the necessary decisions very quickly this week."
As leader of the larger CDU, Laschet would normally be first choice. However, with a confidence and directness that has made him consistently more popular with voters, Soeder has sought to make his popularity a decisive a factor in the race.
Laschet, 60, is widely seen as a candidate who would continue Merkel's legacy, though he has clashed with her over coronavirus restrictions. Soeder, 54, is an astute political operator who has sided with Merkel during the pandemic.
No chancellor has ever come from Soeder's CSU.
(Reporting by Caroline Copley and Paul Carrel Editing by Riham Alkousaa, Raissa Kasolowsky, William Maclean)