Berlin - Two of Germany's 16 states were on the verge Friday of gaining new premiers, with politicians striking coalition deals to set up new governments in Bavaria and Hesse.

Both moves, which will require confirmation in the states' legislatures, could usher in a more fractious period in the final year of Chancellor Angela Merkel's federal coalition government before September 2009 elections.

The two state coalitions are likely to be viewed by voters as test subjects for the next federal government.

After months of political manoeuvring, a Social Democratic (SPD) leader, Andrea Ypsilanti, 51, unveiled details of her bid to topple a conservative incumbent, Roland Koch, and seize the premiership of Hesse.

She said she would invite legislators to elect her as premier on November 4, leading a minority coalition government with the Greens and counting on the votes of the Left party.

Merkel's Christian Democratic Union (CDU) immediately accused Ypsilanti of breaking a pre-election promise not to ally with the Left, which embraces former East German communists and western leftists.

In the state capital of Wiesbaden, Ypsilanti unveiled details of a coalition agreement with leaders of the environmentalist Greens party. They would promote investment in renewable energy and delay the expansion of Frankfurt's airport.

Koch narrowly lost a state legislative election nine months ago. As caretaker premier since, he has sought to weaken the three competing parties which oppose him and has criticized their plans for a loose alliance to vote him out of office. Just two legislators breaking ranks could thwart Ypsilanti's ambitions.

She would not be Germany's first woman state premier, but follows in the Social Democratic footsteps of Heide Simonis, who ran the state of Schleswig-Holstein from 1993 till 2005.

Ypsilanti said her government would comprise 10 Social Democrat ministers and two Greens, including the Greens leader Tarek Al-Wazir as environment minister.

The environmentalists oppose expansion of the airport, which they say already causes too much noise and spoils the landscape. The coalition is to seek a ban on night landings.

In Berlin, CDU general secretary Ronald Pofalla called the new Hesse alliance a "reckless political experiment" based on the SPD "breaking a promise" not to link up with the Left in the west.

The CDU has suggested that the SPD may ultimately seek a federal alliance with the Left, which is anathema to many voters in western Germany. Ypsilanti has also faced opposition to the alliance in her own SPD ranks.

In Bavaria, Christian Social Union (CSU) leader-designate Horst Seehofer, 59, said he had reached terms with the smaller Free Democrat Party (FDP) to rule jointly.

The FDP said it would be allocated two ministries and had won a promise to block legislation which would have allowed police to enter private homes to plant surveillance devices in terrorism suspects' computers.

Seehofer is to seek election as premier by the Bavarian legislature on Monday, with success as good as certain.

Merkel is allied federally with both the CSU and SPD and has struggled to rein in their independent tendencies in light of the upcoming German general election.

She has made no secret of her preference for a coalition with the FDP, which is in opposition at federal level. A successful Bavarian CSU-FDP coalition would make the prospect of a nationwide CDU-CSU- FDP coalition easier for voters to envisage.

The Bavaria-only CSU has similar policies to Merkel's own Christian Democrats, but has sometimes sniped at her rule. Seehofer is set to retire as federal agriculture and consumer affairs minister to become premier in Munich.

The CSU last month lost a third of its traditional support in a state legislative election. The CSU premier, Guenther Beckstein, announced his resignation, clearing the way for Seehofer. (dpa)