Dec 30 (Reuters) - Most major stock markets in the Gulf fell in early trade on Thursday over concerns the Omicron coronavirus variant could slow the economy heading into the new year. In Abu Dhabi, the index (.ADI) dropped 0.9%, dragged down by a 1.6% fall in the country"s largest lender, First Abu Dhabi Bank (FAB.AD). Daily coronavirus infections in the United Arab Emirates, the Gulf region"s tourism and commercial hub, crossed 2,000 for the first time since June. Authorities on Wednesday reported 2,234 new infections in the past 24 hours, without breaking down the cases by COVID-19 variants. Dubai"s main share index (.DFMGI) lost 0.5%, hit by a 0.7% fall in top lender Emirates NBD (ENBD.DU) and a 0.6% decline in sharia-compliant lender Dubai Islamic Bank (DISB.DU). Dubai, which is hosting the Expo until the end of March and whose economy relies heavily on the travel industry, has not yet reintroduced restrictions that were largely lifted in mid-2020. Saudi Arabia"s benchmark index (.TASI) gained 0.3%, with Al Rajhi Bank (1120.SE) rising 0.3%, while Saudi Arabian Mining Company (1211.SE) advanced 1.3%. Oil prices, a key catalyst for the Gulf"s financial markets, rose to extend several consecutive days of gains, buoyed by data showing U.S. fuel demand holding up well despite soaring Omicron coronavirus infections. read more Saudi King Salman said on Wednesday the OPEC+ production agreement was "essential" to oil market stability and stressed the need for producers to comply with the pact. read more The Qatari index (.QSI) eased 0.1%, with Qatar National Bank (QNBK.QA) losing 0.8%.