Denkov's resignation paved the way for GERB party to lead the government for nine months as agreed following last year's elections.

"I accept this mandate with a sense of responsibility as Bulgaria needs stability," Gabriel, who is also an ex-European Commissioner for Digital Economy, told reporters

Minutes later she told reporters that the "We Continue the Change" (party) asked for 24 hours to discuss details.

"I hope that within the next 24 hours we will finalise the agreement, we have no differences on country's priorities," she said.

GERB and a pro-Western bloc led by "We Continue to Change", which Denkov represents agreed last year that Gabriel would take over as prime minister, after Denkov completes his nine-month term.

Earlier this month, GERB said Gabriel should keep her position as foreign minister while she is prime minister and suggested rotation every 15 months instead of nine months.

In elections last April, GERB came first, winning 69 seats in the 240-seat parliament. The bloc led by We Continue to Change won 64 seats.

(Reporting by Stoyan Nenov, Writing by Aleksandar Vasovic; Editing by Bernadette Baum)