Swedish regulators have raided leading local bourse operator Nasdaq OMX Group in a competition probe sparked by a complaint from a small local rival, officials said on Thursday.

The raid was carried out last month and was prompted by a complaint filed by new marketplace Burgundy about the actions of U.S. telecoms company Verizon .

The competition authority expanded its probe to include Nasdaq OMX, according to court documents.

We are cooperating fully with the authorities, said a Nasdaq OMX spokesman in Stockholm.

Burgundy chief executive Olof Neiglick told Reuters his company had reached an agreement in 2010 to house its servers in a data center owned by Verizon, which also houses the Nasdaq OMX servers and those of major clients like banks.

He said Verizon later canceled the agreement.

A spokeswoman for the Competition Authority confirmed a raid had taken place.

Court documents said: KKV (the competition authority) wishes to investigate whether OMX has applied pressure on Verizon or threatened to punish Verizon if Verizon concludes an agreement with a competitor to OMX.

According to the KKV, OMX and Verizon's actions mean that Burgundy risks being shut of the market in bourse trade with Nordic securities, the document said.

(Reporting by Patrick Lannin and Mia Shanley in Stockholm; Additional reporting by Karolina Tagaris in London; Editing by Richard Chang and Dan Lalor)