MEXICO CITY, June 26 (Reuters) - Mexican state oil firm Pemex has produced an average of 1.68 million barrels per day (bpd) of crude oil in June, the company's chief executive said on Wednesday, slightly above the 1.66 million bpd registered in May.

Speaking at a news conference, Pemex Chief Executive Octavio Romero said by the end of the year the company's oil production should reach 1.83 million bpd, with additional production from several fields under development.

Romero denied that Pemex, the world's most indebted oil company, is having problems paying suppliers. (Reporting by Ana Isabel Martinez; Writing by Julia Love; Editing by Bill Trott)