Turkey's ruling AK Party is seen losing its parliamentary majority in a June 7 election and may have to form a coalition government, according to the results of a survey by pollster SONAR seen by Reuters on Monday.

The poll put AKP support at 41 percent, the main opposition Republican People's Party (CHP) at 26 percent, the nationalist MHP at 18.1 percent and the pro-Kurdish HDP at 10.4 percent, just above the 10 percent threshold needed to enter parliament.

It was the second poll within days by a widely watched pollster pointing to AK Party support just above 40 percent, hitting sentiment among investors which have been pricing in a majority for the AK Party.

Previous surveys by other pollsters had put AKP support around the 45-47 percent level.

The lira eased to 2.61 against the dollar from 2.5961 on Friday. Istanbul shares fell 0.35 percent and the benchmark 10-year bond yield rose to 9.15 from 9.12 percent on Friday.

A level of support for the AK Party indicated by the latest polls would make it very hard for it to achieve constitutional changes sought by its co-founder, President Tayyip Erdogan, who wants stronger executive powers.

(Reporting by Ercan Gurses; Writing by Daren Butler and Ece Toksabay; Editing by David Dolan and Toby Chopra)