Bengaluru, February 24 (Reuters) - Gulf stock markets reversed early trends at the close on Tuesday, as investors took a cautious stance in a volatile session ahead of a third round of nuclear talks between the United States and Iran scheduled for Thursday.

The Saudi stock market index fell 0.7 percent after a modest recovery in the previous session, as the kingdom's budget deficit widened on a quarterly basis due to rising spending.

The losses were widespread, with shares of Saudi Telecom falling 2.1 percent and shares of state-owned oil giant Aramco dropping 0.5 percent.

Reuters, citing trade sources, reported that Aramco sold several cargoes of ultra-light crude oil from its $100 billion Jafurah gas plant to major U.S. companies and an Indian refinery, ahead of its first export later this month.

Antoine Naddaf, regional director of Jeff Trade, said the market is well-positioned to benefit from its strong fundamentals as external pressures subside.

In Dubai, the main stock index fell 0.6 percent, after rising nearly 2 percent in the previous session.

Emirates NBD was affected by the decline in bank stocks, recording its biggest daily drop in nearly three months, falling by more than four percent, while Dubai Islamic Bank fell 1.6 percent.

The Abu Dhabi stock market index closed unchanged, maintaining its gains after rebounding in the previous session from a two-day sell-off at record lows. ADNOC Gas shares fell 0.3 percent, while Abu Dhabi Commercial Bank shares rose 0.3 percent, continuing their upward trend that began on Monday.

Naddaf noted that the Abu Dhabi market still has upward potential, supported by strong fourth-quarter results and a robust economic outlook, although oil price volatility remains a key point of note.

Oil prices, a key driver for Gulf markets, hovered near seven-month highs as traders assessed supply risks from any military escalation ahead of another round of nuclear talks between the United States and Iran.

The Qatari index rose 0.1 percent, driven by gains in bank stocks. Shares in Qatar National Bank, the region's largest lender, climbed 0.5 percent, extending its momentum from its best daily performance since mid-October in the previous session.

US private equity firm FiveC Investment Partners has announced a strategic partnership with the Qatar Investment Authority to expand its direct lending platform.

Outside the Gulf region, Egypt's blue-chip index fell 0.9 percent after a sell-off led by bank stocks. Shares in Commercial International Bank, the country's largest private bank, dropped 1.3 percent.

Shares of Talaat Moustafa Group fell 1.6 percent, reversing gains from the previous session, after the real estate developer announced on Monday that its annual profits had risen 43 percent and it had been upgraded to the mid-cap category within the FTSE Russell global equity index series.

The International Monetary Fund said its board of directors will meet on February 25 to review the Fund's Extended Fund Facility program in Egypt, a move that could open the door to the disbursement of $2.3 billion.