UPDATE 1-City hall in Brazil's Maceio requests new damages deal with Braskem

(Recasts with new compensation agreement request, adds more details on agreement, context)

SAO PAULO, Dec 6 (Reuters) - The city hall of Brazil's northeastern city of Maceio has asked to negotiate a new compensation agreement with petrochemical firm Braskem over the expansion of a risk area linked to sinking ground in the city, it said on Wednesday.

The request comes five months after the city and Braskem reached an agreement for the payment of 1.7 billion reais ($347.14 million).

Maceio's civil defense office warned last week that Braskem's salt mine number 18, located near a lake in the Mutange neighborhood, was at imminent risk of collapse.

Initially, the city had confirmed a request to reopen the talks about the agreement made in July, but later clarified the deal "remains valid" and would seek a new settlement to include "fresh damages".

The company's rock salt mining activities in the area, which were halted in 2019, led to soil subsidence that forced the interdiction of several neighborhoods in Maceio.

The updated risk map, released at the end of November, was the basis for a federal court to include the Bom Parto neighborhood in Braskem's relocation program, according to the city government.

Braskem has set aside 14.4 billion reais since 2018 to address issues related to the sinking ground in the city, which authorities attributed to its decades-long salt mining activities carried in Maceio's underground.

Braskem declined to comment on the matter.

($1 = 4.8971 reais) (Reporting by Alberto Alerigi Jr.; Writingby Peter Frontini; Editing by Steven Grattan and Chizu Nomiyama)