UPDATE 1-Kuwait vote dents critics' hopes for reforms

(Adds details of elections, analysts, background)

By Rania El Gamal and Ulf Laessing

KUWAIT, May 18 (Reuters) - Hopes for economic reform in Kuwait were dealt a blow by a parliamentary election in which Islamists and tribal alliances maintained their grip on power and women failed to win any seats, critics said.

Twenty-eight members of the previous 50 seat National Assembly, beset by political squabbling and delays to legislation, were re-elected in Saturday's vote, according to figures carried by official media on Sunday.

Kuwait's stock exchange , the second-largest in the Arab world, edged down after the results were announced.

"Everybody already says this is an unstable assembly and will not continue for long," said Nabeela al-Anjari, a women's activist and former candidate in the 2006 election.

"The majority will support the existing powers who will follow only their interests ... We are heading towards a critical period of crises."

Ruler Sheikh Sabah al-Ahmad al-Sabah dissolved parliament in March to end a standoff with the cabinet that had stalled political life and delayed economic reforms.

The last assembly focused on questioning ministers over their policy, forcing several to resign. The OPEC producer has yet to appoint an oil minister since the last quit in November.