The first round of coalition talks between German Chancellor Angela Merkel's conservative bloc and its main opponent ended on Friday with both sides agreeing to continue the talks in 10 days.

The atmosphere of the exploratory talks on Friday was "good, sober and constructive," Hermann Groehe, secretary general of Merkel's Christian Democratic Union (CDU), told reporters after the three-hour meeting.

Andrea Nahles, secretary general of the center-left Social Democratic Party (SPD), said that the talks were in an "open-minded atmosphere."

Lacking a majority in the new parliament after elections on Sept. 22, Merkel's bloc of CDU and its Bavarian sister party Christian Social Union (CSU) needs a partner to rule the Europe's largest economy for the next four years.

A repeat of so-called "grand coalition" between CDU/CSU and SPD, as in Merkel's first term in 2005-2009, was supported by 58 percent of Germans. The idea, however, was rejected by a majority of SPD members, recent polls showed.

SPD leaders said last week that the decision of whether to form a coalition with the Union would be made by the party's 470,000 members.

The main hurdle is their different views on various domestic policies, including tax increases and setting a national statutory minimum wage.

During its election campaign, SPD stressed greater social justice and reiterated the plan to introduce a national minimum wage of 8.50 euros (11.35 U.S. dollars) per hour. The party also wants to raise taxes on incomes above 100,000 euros to 49 percent from 42 percent.

However, Merkel said such tax hike plans would risk spoiling the good situation in the country. The CDU/CSU rejected tax increases in its campaign and supports minimum wage deals struck by employers and trade unions in different industry sectors and regions.

Nahles said on Monday the horse-trading was expected to last a long time, and a new government was expected to appear "in December or January."

CDU/CSU is also scheduled to hold exploratory talks on Thursday with the Greens, a much weaker negotiator that only gained 8.4 percent in the election.

Theoretically, Merkel's conservative bloc could also ally with the Greens to reach a majority in the government, despite the fact that the two sides differ on various issues.

"We are serious about the talks," Katrin Goering-Eckardt, one of the party's candidates for chancellor, said in a recent interview.