Hamburg  - Germany's Christian Democrats (CDU) and the Greens signed their first-ever coalition agreement at state level in Hamburg's City Hall Thursday.

The deal, which comes after five weeks of intensive political talks, has yet to be approved by the executives of the two parties, but observers expected the city-state would soon be ruled by the first-ever coalition of this stripe.

The Greens, who have in the past tended to pair with the, meet on April 27 to finalize the agreement.

The CDU, headed at federal level by Chancellor Angela Merkel, meet the following day.

Hamburg Mayor Ole von Beust, who ran the city without a coalition partner and lost his absolute majority in the legislature in the February 24 elections, aims to have himself confirmed in office in a vote on May 7.

The coalition talks centred on two key themes: CDU plans to build a large coal-fired power station within the city bounds and to deepen the River Elbe so that the largest container ships can reach Europe's third-largest port. The Greens are opposed to both. (dpa)